Change logic to determine whether the managed BIG-IPS's are deployed by Nova
Change logic to determine whether the managed BIG-IPS's are deployed by Nova

Issues:
Fixes #850

Problem:
Sending the interface information in the agent configuration could
possibly exceed DB storage limits.

Analysis:
Modify the algorithm to determine if this condition exists by using
the new flag, 'nova_managed', provided by the agent configuration.

Tests:
TBI

F5Networks/f5-openstack-lbaasv2-driver,richbrowne/f5-openstack-lbaasv2-driver,F5Networks/f5-openstack-lbaasv2-driver,jputrino/f5-openstack-lbaasv2-driver,jputrino/f5-openstack-lbaasv2-driver,jlongstaf/f5-openstack-lbaasv2-driver,richbrowne/f5-openstack-lbaasv2-driver,jlongstaf/f5-openstack-lbaasv2-driver