Update php.md

Author: pjwiseman

manual/en-US/coding-standards/chapters/php.md

@@ -481,7 +481,7 @@ $query = $db->getQuery(true);
 // Build the query programatically (using chaining if desired).
 $query->select('u.*')
 	// Use the qn alias for the quoteName method to quote table names.
-	->from($db->qn('#__users').' AS u'));
+	->from($db->qn('#__users') . ' AS u'));
 
 // Tell the database connector what query to run.
 $db->setQuery($query);