[l3vpn_ecmp]If vpn name is changed and other configurations retained, all the routes from previous vpn is populated in new vpn.

Description
=====================================
If vpn name is changed and other configurations retained, all the routes from previous vpn is populated in new vpn.

Topology
=================================
3CSS, 1 DC-GW, 6 VMs, 2 each on each CSS.

Build used
==================================
distribution-karaf-0.6.0-20170522.002211-5360.zip

Steps to repro
==================================
1)Do the basic vxlan configuration for one CSS.
2)Configure mpls over gre.Check it is configured properly.
3)Form bgp neigborship between Controller and DC-GW and check check bgp neighborship.
4)Configure two VMs each on CSS-1, CSS-2 and CSS-3 using nova command, configure bgvpn update with one rd.Check whether it is advertised to DC-GW.
5)Check these VM entries updated in "show ip route" in vpn context.
6)Remove the existing vpn "vpn1" from smart edge and configure a new vpn "testVpn1" with all the rd/rt confiurations same as "vpn1".
7)All the ip routes are populated in "testVpn1", however the nova command used to create vpn is using vpn1 only.