Adjust oslo logging to provide adapter is enabled for

In python 2.6 the isEnabledFor adapter method is not found
since it was added in 2.7+ so to enable its usage in openstack
which can want to use this method add it on when in python 2.6
and just call the parent method on other versions.

Closes-Bug: #1343544

Change-Id: I5c3ba91cb1a8555d649fffc1377e9e9dfe92fea8
Merge "Adjust oslo logging to provide adapter is enabled for"