BaseException.message is deprecated since Python 2.6
BaseException.message is deprecated since Python 2.6

PEP 352 deprecated the message attribute of the BaseException class.
Using the message attribute will result in warnings like this:

DeprecationWarning: BaseException.message has been deprecated as of Python 2.6

Using unicode(exc) is the suggested replacement.

Change-Id: Ibf3c56e4baa6ad83e2b95a948787e9d02cf074d4

openstack/oslo.db,malor/oslo.db,JioCloud/oslo.db,openstack/oslo.db,magic0704/oslo.db,vikt0rs/oslo.db,akash1808/oslo.db,varunarya10/oslo.db