Removed unneeded message files from 'user'

[reithor]

Removed:

es_ES/user/messages.es.xlf
pt_PT/user/messages.pt.xlf
nb_NO/user/messages.nb.xlf
en_US/user/messages.en_US.xlf
de_DE/user/messages.de.xlf
hr_HR/user/messages.hr.xlf
el_GR/user/messages.el.xlf
ru_RU/user/messages.ru.xlf
hu_HU/user/messages.hu.xlf
fr_FR/user/messages.fr.xlf
it_IT/user/messages.it.xlf
zh_HK/user/messages.zh_HK.xlf

• None of the above contain translated strings.
• There is no messages..xlf file in i18n/user/

PR keeps files that contain some translated strings :

ach_UG/user/messages.ach-UG.xlf
ja_JP/user/messages.ja.xlf
pl_PL/user/messages.pl.xlf