Add search and limit to getGroups search in groupExists implementation

lib/group/backend.php

@@ -115,7 +115,7 @@ abstract class OC_Group_Backend implements OC_Group_Interface {
 	 * @return bool
 	 */
 	public function groupExists($gid){
-		return in_array($gid, $this->getGroups());
+		return in_array($gid, $this->getGroups($gid, 1));
 	}
 
 	/**