react to trig-pend only if we have nothing else to do

react to trig-pend only if we have nothing else to do

If a package is triggered dpkg frequently issues two messages about it
causing us to make a note about it both times which messes up our
planned dpkg actions view. Adding these actions if we have nothing else
planned fixes this and should still be correct as those planned actions
will deal with the triggering just fine and we avoid strange problems
like a package triggered before its removed…