virsh: domain: Use inactive XML when unplugging interface with --config
virsh: domain: Use inactive XML when unplugging interface with --config

Similary to cmdDetachDisk fetch the inactive definition when --config
is specified as the active may not contain the network interface
if it was plugged with --config.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1056902

fabianfreyer/libvirt,nertpinx/libvirt,eskultety/libvirt,agx/libvirt,VenkatDatta/libvirt,crobinso/libvirt,olafhering/libvirt,eskultety/libvirt,elmarco/libvirt,nertpinx/libvirt,jardasgit/libvirt,andreabolognani/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,agx/libvirt,elmarco/libvirt,andreabolognani/libvirt,jardasgit/libvirt,agx/libvirt,jardasgit/libvirt,jfehlig/libvirt,datto/libvirt,crobinso/libvirt,taget/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,taget/libvirt,taget/libvirt,libvirt/libvirt,jfehlig/libvirt,andreabolognani/libvirt,datto/libvirt,elmarco/libvirt,zippy2/libvirt,crobinso/libvirt,rlaager/libvirt,agx/libvirt,rlaager/libvirt,shugaoye/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,jardasgit/libvirt,eskultety/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,shugaoye/libvirt,olafhering/libvirt,olafhering/libvirt,libvirt/libvirt,fabianfreyer/libvirt,libvirt/libvirt,datto/libvirt,datto/libvirt,eskultety/libvirt,VenkatDatta/libvirt,shugaoye/libvirt,elmarco/libvirt,datto/libvirt,elmarco/libvirt,zippy2/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,olafhering/libvirt,libvirt/libvirt,jfehlig/libvirt,taget/libvirt,crobinso/libvirt,zippy2/libvirt,shugaoye/libvirt,nertpinx/libvirt,rlaager/libvirt,nertpinx/libvirt,rlaager/libvirt,zippy2/libvirt,eskultety/libvirt,rlaager/libvirt,agx/libvirt,taget/libvirt