roles/aurweb: Randomize that start time of the aurweb-git service

Added RandomizedDelaySec to make the aurweb-git.service to start on
a different time than the borg backup, so the machine does not hammered
by both running at the same time.

roles/aurweb/templates/aurweb-git.timer.j2

@@ -3,6 +3,7 @@ Description=Git gc & repack AUR
 
 [Timer]
 OnCalendar=daily
+RandomizedDelaySec=1h
 
 [Install]
 WantedBy=timers.target