sync oslo db/sqlalchemy module

sync oslo db/sqlalchemy module to grab "Mark sql_connection with secret
flag" change.

fixes bug 1160680

Change-Id: Id48419624c41eea5a0f2e130d7cdbe8a8f0a9118
Merge "sync oslo db/sqlalchemy module"
Merge remote-tracking branch 'm_src_repo/master' into build-temp