Shorten a long exception message.

laravel/lang.php

@@ -149,7 +149,7 @@ class Lang {
 			return array($segments[0], implode('.', array_slice($segments, 1)));
 		}
 
-		throw new \InvalidArgumentException("Invalid language line [$key]. A specific line must be specified.");
+		throw new \InvalidArgumentException("Invalid language line [$key].");
 	}
 
 	/**
@@ -188,4 +188,4 @@ class Lang {
 		return $this->get();
 	}
 
-}
+}