Prevent interface map from being built for neutron_server container

This patch updates the provider_network library by removing neutron_server
from the list of groups that require provider interface maps, as
neutron_server is not in-path of instance traffic, and all interface mappings
should exist only where network agents are configured. Removing this logic
will allow container_interface to become an optional parameter for provider
network definitions.

Change-Id: I5bfa14e0b7d97eb75756b7e40c93f48ae13fe087

library/provider_networks

@@ -253,8 +253,7 @@ class ProviderNetworksParsing(object):
                 if (
                     set(
                         net["network"]["group_binds"]
-                    ).intersection(group_names) or
-                    "neutron_server" in group_names
+                    ).intersection(group_names)
                 ):
                     if 'net_name' in net['network']:
                         if is_metal: