Remove remaining 2.0 warning
Remove remaining 2.0 warning

with the merge of If6b792e57c8c5dff205419644ab68e631575a2fa
in SQLAlchemy we can remove this last 2.0 deprecation warning
filter.

Change-Id: I2a615dc70432e9b6a89a551f405c2a81bcbb8981

sqlalchemy/alembic,zzzeek/alembic