As discussed in the Liberty Design Summit "Moving apps to Python 3"
cross-project workshop, the way forward in the near future is to
switch to the pure-python PyMySQL library as a default.
https://etherpad.openstack.org/p/liberty-cross-project-python3
This change handles only common files and Config Reference.
Change-Id: I8d60ec2ca85c3099fc39c293ada0a78fffb28599