Fix ipa-ccache-sweeper activation timer and clean up service file

Added OnActiveSec=12h to start the timer cycle because OnUnitActiveSec setting alone never triggers the timer after boot as there has not been transition between active and inactive state.
Removed [Install] section from sweeper.service as it is not needed

Fixes: https://pagure.io/freeipa/issue/9231
Signed-off-by: Jesse Sandberg <jesse.sandberg@netcode.fi>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

init/systemd/ipa-ccache-sweep.service.in

@@ -8,6 +8,3 @@ Environment=LC_ALL=C.UTF-8
 ExecStart=@libexecdir@/ipa/ipa-ccache-sweeper
 PrivateTmp=yes
 User=ipaapi
-
-[Install]
-WantedBy=multi-user.target

init/systemd/ipa-ccache-sweep.timer.in

@@ -2,6 +2,7 @@
 Description=Remove Expired Kerberos Credential Caches
 
 [Timer]
+OnActiveSec=12h
 OnUnitActiveSec=12h
 
 [Install]