Merge pull request #18300 from JJRcop/localhost_is_always_admin

Localhost and .dmbs opened with dreamseeker always get admin

code/modules/client/client_procs.dm

@@ -113,6 +113,12 @@ var/next_external_rsc = 0
 	directory[ckey] = src
 
 	//Admin Authorisation
+	var/localhost_addresses = list("127.0.0.1", "::1")
+	if(!address || (address in localhost_addresses))
+		var/datum/admin_rank/localhost_rank = new("!localhost!", 65535)
+		if(localhost_rank)
+			var/datum/admins/localhost_holder = new(localhost_rank, ckey)
+			localhost_holder.associate(src)
 	if(protected_config.autoadmin)
 		if(!admin_datums[ckey])
 			var/datum/admin_rank/autorank
@@ -127,7 +133,7 @@ var/next_external_rsc = 0
 				admin_datums[ckey] = D
 	holder = admin_datums[ckey]
 	if(holder)
-		admins += src
+		admins |= src
 		holder.owner = src
 
 	//preferences datum - also holds some persistant data for the client (because we may as well keep these datums to a minimum)