Fix haproxy cfg unit test

Check if an option was already registered by one of the previous tests

Fixes bug 1157094

Change-Id: Ieaa6e4b3647fb64ce1928b8564e4a41e68c97e74
Load all the necessary database tables when running cisco plugin

In Cisco plugin, Remove redundant/unnecessary calls to configure_db().
Make sure that all the database models are loaded before calling
configure_db()

fixes bug #1155121

Change-Id: I27d5dda512140f0553b311b35678c82f729fa854