Sync log from oslo

Update the copy of oslo's log to oslo-incubator
0533894d6bfacd82a371bccd628b61d5016032cd.

This is the first step towards supporting Python 3 in
os-collect-config.

Change-Id: If282091d7f0cbd4e2ce90d70c066bb11cbf56d38
Merge "Sync log from oslo"