Fixed From Header check in route REGISTRAR

Ported from 2.0 branch

etc/ser-oob.cfg

@@ -839,11 +839,11 @@ route[REGISTRAR]
 
 	# check if the authenticated user is the same as the request originator
 	# you may uncomment it if you care, what uri is in From header
-	#if (!lookup_user("$fu.uid", "@from.uri")) {
+	#if (!lookup_user("$fr.uid", "@from.uri")) {
 	#	sl_reply("404", "Unknown user in From");
 	#	drop;
 	#}
-	#if ($fu.uid != $tu.uid) {
+	#if ($fu.uid != $fr.uid) {
 	#	sl_reply("403", "Authentication and From-Header mismatch");
 	#	drop;
 	#}