Optimization: use logging.disable() to set logging level.
Optimization: use logging.disable() to set logging level.

This reduces the overhead of each logging call.

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