Using substitution for Python String
Using substitution for Python String

This patch using String substitution instead of String concatenation.

Change-Id: I1faabeb1943449ae60232e08a842652c86793a45

apporc/neutron,MaximNevrov/neutron,klmitch/neutron,eayunstack/neutron,noironetworks/neutron,mahak/neutron,igor-toga/local-snat,apporc/neutron,huntxu/neutron,wolverineav/neutron,klmitch/neutron,mahak/neutron,noironetworks/neutron,cloudbase/neutron,dims/neutron,openstack/neutron,MaximNevrov/neutron,eayunstack/neutron,igor-toga/local-snat,bigswitch/neutron,mahak/neutron,huntxu/neutron,openstack/neutron,openstack/neutron,wolverineav/neutron,bigswitch/neutron,sebrandon1/neutron,dims/neutron,sebrandon1/neutron,cloudbase/neutron