fix(systemd): fix env vars with special chars

Resolve issue with environment variables containing special characters
when loaded via systemd. Adjusted `ExecStart` to invoke `podman` through
`runagent`, ensuring proper handling of systemd's variable parsing
quirks.

imageroot/systemd/user/freepbx.service

@@ -9,7 +9,6 @@ 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