[ticket/9949] $user->lang() uses last int-value to get the key not first

The comment in the code says: "We now get the first number passed and will
select the key based upon this number". But the loop over the arguments is not
left and therefore it uses the last int-value not the first one.

PHPBB3-9949

phpBB/includes/session.php

@@ -1966,6 +1966,7 @@ class user extends session
 
 					$key_found = $num;
 				}
+				break;
 			}
 		}