Greeter to not respect xorg screen resolution settings on multimonitor setup

[NickVolt77]

 * slick-greeter version 1.5.6
 * Distribution - Manjaro Cinnamon
 * Graphics hardware *and* driver used: Intel HD (i5-5300U) stock driver
 * 64 bit

My setup is:
HP 840 G2 with 14 inch 1366x768 + BenQ 24 inches 1920x1080

Issue
Since few last updates login screen is broken. In monitor I have probably 1366x768 resolution (login screen is blury and big), on laptop screen login screen seems to be moved left top (thera are black space on right and bottom of the screen). It seems, that works in mirror setup with the same resolution for laptop screen and external screen.

Steps to reproduce
Start pc with Manjaro Cinnamon on dual monitor setup (HD+FHD) with Intel HD.

Expected behaviour
Login screen should have 1366x768 on laptop screen and FHD on FHD external screen. Screen resoultion and setup should be imported from xorg/Cinnamon setup.

Other information
Command --version returns this:
`
[+0,00s] DEBUG: _g_io_module_get_default: Found default implementation dconf (DConfSettingsBackend) for ‘gsettings-backend’
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for background with /usr/share/backgrounds/greeter_default.jpg
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for background-color with #263138
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for logo to default
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for other-monitors-logo to default
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for theme-name with Adapta-Nokto-Eta-Maia
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for icon-theme-name with Papirus-Dark-Maia
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for font-name with 'Cantarell 11'
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for play-ready-sound to default
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for xft-hintstyle with hintfull
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for xft-rgba to default
[+0,00s] DEBUG: settings.vala:161: Overriding dconf setting for enable-hidpi with auto
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for only-on-monitor to default
[+0,00s] DEBUG: settings.vala:170: Resetting dconf setting for clock-format to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for draw-user-backgrounds to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for stretch-background-across-monitors to default
[+0,00s] DEBUG: settings.vala:179: Overriding dconf setting for draw-grid
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-hostname to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-power to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-a11y to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-clock to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-keyboard to default
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for show-quit to default
[+0,00s] DEBUG: settings.vala:179: Overriding dconf setting for xft-antialias
[+0,00s] DEBUG: settings.vala:188: Resetting dconf setting for activate-numlock to default
[+0,00s] DEBUG: settings.vala:206: Resetting dconf setting for xft-dpi to default
[+0,00s] DEBUG: settings.vala:224: Resetting dconf setting for hidden-users to default
[+0,00s] DEBUG: settings.vala:224: Resetting dconf setting for group-filter to default
[+0,00s] DEBUG: slick-greeter.vala:632: HiDPI support: auto
/usr/bin/slick-greeter-check-hidpi:17: DeprecationWarning: Gdk.Screen.get_primary_monitor is deprecated
primary = screen.get_primary_monitor()
/usr/bin/slick-greeter-check-hidpi:19: DeprecationWarning: Gdk.Screen.get_monitor_geometry is deprecated
rect = screen.get_monitor_geometry(primary)
/usr/bin/slick-greeter-check-hidpi:20: DeprecationWarning: Gdk.Screen.get_monitor_width_mm is deprecated
width_mm = screen.get_monitor_width_mm(primary)
/usr/bin/slick-greeter-check-hidpi:21: DeprecationWarning: Gdk.Screen.get_monitor_height_mm is deprecated
height_mm = screen.get_monitor_height_mm(primary)
/usr/bin/slick-greeter-check-hidpi:22: DeprecationWarning: Gdk.Screen.get_monitor_scale_factor is deprecated
monitor_scale = screen.get_monitor_scale_factor(primary)
[+0,27s] DEBUG: unsetenv() is not thread-safe and should not be used after threads are created
[+0,28s] DEBUG: _g_io_module_get_default: Found default implementation gvfs (GDaemonVfs) for ‘gio-vfs’
[+0,33s] DEBUG: slick-greeter.vala:651: Starting slick-greeter 1.5.6 UID=1000 LANG=pl_PL.UTF-8
[+0,33s] DEBUG: slick-greeter.vala:654: Setting cursor
[+0,33s] DEBUG: slick-greeter.vala:668: Loading command line options

`