fix: make sure timer starts running after installation and use more intuitive time units

templates/usr/local/lib/systemd/system/chmod_chown_sftp_uploads.timer.j2

@@ -2,7 +2,8 @@
 Description=timer: set correct permissions for SIPs that were uploaded via SFTP
 
 [Timer]
-OnUnitActiveSec=300
+OnActiveSec=5min
+OnBootSec=1min
 #When activated, it triggers the service immediately if it missed the last start time, for example due to the system being powered off
 Persistent=true
 #Unit to activate when the timer elapses. (default is set to the same name as the timer unit, except for the suffix)