Fixed VRF remove bug in backend
Fixed VRF remove bug in backend

The remove_vrf function built invalid specs to for removing all prefixes
in a VRF.

ettrig/NIPAP,ettrig/NIPAP,SoundGoof/NIPAP,ettrig/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,garberg/NIPAP,ettrig/NIPAP,garberg/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,ettrig/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,SoundGoof/NIPAP,garberg/NIPAP,garberg/NIPAP,SpriteLink/NIPAP,fredsod/NIPAP,bbaja42/NIPAP,bbaja42/NIPAP,SpriteLink/NIPAP,plajjan/NIPAP,bbaja42/NIPAP,plajjan/NIPAP,bbaja42/NIPAP,fredsod/NIPAP,fredsod/NIPAP,plajjan/NIPAP,fredsod/NIPAP,fredsod/NIPAP,plajjan/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,plajjan/NIPAP,plajjan/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,bbaja42/NIPAP,SoundGoof/NIPAP