Add additional check that view exists before proceeding

We assume the array key exists with view but not ID. I have come across some installations where view does not exist and it causes php warnings. So just check it does exist before actually proceeding further as we do with ID.

components/com_content/helpers/legacyrouter.php

@@ -92,6 +92,7 @@ public function build(&$query, &$segments)
 
 		// Are we dealing with an article or category that is attached to a menu item?
 		if ($menuItem !== null
+			&& isset($menuItem->query['view'], $query['view'])
 			&& $menuItem->query['view'] == $query['view']
 			&& isset($menuItem->query['id'], $query['id'])
 			&& $menuItem->query['id'] == (int) $query['id'])