Partial revert of a87afea676375aba4f0ec28228e28df0502e5321

Previously we were setting hostname to $::realm which was intentionally
bogus... that didn't do what was hoped, though, and caused icinga to
bail out and skip a bunch of tests.

Change-Id: If8102cffd4364639522546211690797dae8133a6
Merge "Partial revert of a87afea676375aba4f0ec28228e28df0502e5321" into production