Ling datum antag standarization.

code/modules/mob/mob_helpers.dm

@@ -365,7 +365,7 @@ It's fairly easy to fix if dealing with single letters but not so much with comp
 				if(M.mind in SSticker.mode.syndicates)
 					return 2
 			if("changeling")
-				if(M.mind in SSticker.mode.changelings)
+				if(M.mind.has_antag_datum(/datum/antagonist/changeling,TRUE))
 					return 2
 			if("wizard")
 				if(iswizard(M))