fix(systemd): fix env vars with special chars

Correct handling of environment variables containing special characters
when loaded via systemd. Replaced direct podman execution with runagent
wrapper to ensure proper parsing and execution. Removed unused
EnvironmentFile directive to avoid confusion and potential conflicts.

imageroot/systemd/user/freepbx.service

@@ -9,13 +9,12 @@ After=mariadb.service
 
 [Service]
 Environment=PODMAN_SYSTEMD_UNIT=%n
-EnvironmentFile=%S/state/environment
 WorkingDirectory=%S/state
 Restart=always
 ExecStartPre=/bin/rm -f %t/freepbx.pid %t/freepbx.ctr-id
 ExecStartPre=-runagent install-certificate freepbx
 ExecStartPre=-runagent discover-smarthost
-ExecStart=/usr/bin/podman run \
+ExecStart=runagent /usr/bin/podman run \
     --detach \
     --conmon-pidfile=%t/freepbx.pid \
     --cidfile=%t/freepbx.ctr-id \