Only log tag update message if we actually updated tags.
Only log tag update message if we actually updated tags.

TrimBiggs/calico,alexhersh/calico,neiljerram/felix,TrimBiggs/calico,neiljerram/felix,matthewdupre/felix,neiljerram/felix,neiljerram/felix,alexhersh/calico,Metaswitch/calico,matthewdupre/felix,Metaswitch/calico