Fixed bug were no changes would cause an error

This is because diff will return an error status, this will trigger -e
to exit.

Change-Id: I0c0c3f82674b399b2b5cec8bfe86a46273b69ed9
Only restart nagios if there was a change

Change-Id: I5dd8d6141597af649e2eb3681990c68dc09841ba