another questionable "optimization": de used tulip_ifstart_one instead

another questionable "optimization": de used tulip_ifstart_one instead
of tulip_ifstart if the sendqueue was empty, but only if altq wasn't
compiled in (i. e., that's a _compile time_ decision and not based on
wether altq was actually used).
just use tulip_ifstart all the time, as before in our regular kernels.
kill tulip_ifstart_one completely.
makes sense to sthen