Remove obsolete autovacuum comment.

This comment seems to refer to some stuff that was removed during
development in 2005.

Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/aRJFDxKJLFE_1Iai%40nathan

src/backend/postmaster/autovacuum.c

@@ -3158,11 +3158,6 @@ relation_needs_vacanalyze(Oid relid,
 			vac_ins_scale_factor * reltuples * pcnt_unfrozen;
 		anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
 
-		/*
-		 * Note that we don't need to take special consideration for stat
-		 * reset, because if that happens, the last vacuum and analyze counts
-		 * will be reset too.
-		 */
 		if (vac_ins_base_thresh >= 0)
 			elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)",
 				 NameStr(classForm->relname),