trivial: removed unused networks var from os-tenant-networks:create
trivial: removed unused networks var from os-tenant-networks:create

This simply removes an unused variable from the create method
in the os-tenant-networks API.

Note that this is also in the legacy v2 API extension code but
that's going to be removed so I'm not fixing it here.

Change-Id: I172acbdc245769fe6415f0bdb5e001754c1f83eb

Juniper/nova,bigswitch/nova,gooddata/openstack-nova,sebrandon1/nova,mahak/nova,cloudbase/nova,jianghuaw/nova,openstack/nova,rahulunair/nova,rajalokan/nova,bigswitch/nova,vmturbo/nova,Juniper/nova,rajalokan/nova,vmturbo/nova,klmitch/nova,jianghuaw/nova,hanlind/nova,jianghuaw/nova,mikalstill/nova,mikalstill/nova,hanlind/nova,vmturbo/nova,mahak/nova,mikalstill/nova,rajalokan/nova,klmitch/nova,openstack/nova,gooddata/openstack-nova,gooddata/openstack-nova,cloudbase/nova,gooddata/openstack-nova,rahulunair/nova,phenoxim/nova,alaski/nova,cloudbase/nova,jianghuaw/nova,klmitch/nova,Juniper/nova,alaski/nova,openstack/nova,mahak/nova,klmitch/nova,sebrandon1/nova,vmturbo/nova,rajalokan/nova,hanlind/nova,Juniper/nova,sebrandon1/nova,phenoxim/nova,rahulunair/nova