Time to drop --{en|dis}able-hba from configure

The 'configure' script currently says

	checking setting HBA... enabled

which is hardly needed any more.  I just grepped through the whole
tree, and there is no occurrence of "NOHBA" outside of configure -- as
there shouldn't be now that the pg_hba.conf file is used to select the
authentication scheme(s) to be used.  (Which, by the way, was a Smart
Move, in my opinion.  Things were too confusing as they were.)

-tih
-- 
Popularity is the hallmark of mediocrity.  --Niles Crane, "Frasier"