Add debug output for XRv
Add debug output for XRv

I'm seeing some strange failures where the bootstrap configuration fails on XRv
routers, in particular the configuration of the management interface fails and
I suspect we are so quick in trying to configure it the router hasn't properly
started yet (despite saying so). I'm adding this `show interface description`
so that we can get see in the trace log if this is indeed the case.

mzagozen/vrnetlab,plajjan/vrnetlab,bdreisbach/vrnetlab,bdreisbach/vrnetlab,mzagozen/vrnetlab,holmahenkel/vrnetlab,holmahenkel/vrnetlab,plajjan/vrnetlab