fixed To user lookup for REGISTER; thansk to Michal

etc/ser.cfg

@@ -10,7 +10,7 @@
 # what can be achieved with the SER config script language.
 #
 # If you look for a simpler version with a lot less dependencies
-# please refer to the ser-simple.cfg file in your SER distribution.
+# please refer to the ser-basic.cfg file in your SER distribution.
 
 # To get this config running you need to execute the following commands
 # with the new serctl (the capital word are just place holders)
@@ -322,7 +322,7 @@ route[REGISTRAR]
 		};
 
 		# check if the authenticated user is the same as the target user
-		if (!lookup_user("$tu", "@from.uri")) {
+		if (!lookup_user("$tu", "@to.uri")) {
 			sl_send_reply("404", "Unknown user");
 			drop;
 		}