add cors header for wellknown

Author: ylebre

solid/lib/WellKnown/OpenIdConfigurationHandler.php

@@ -116,6 +116,8 @@ private function respond($response) {
 				$result->addHeader($header, $value);
 			}
 		}
+
+		$result->addHeader("Access-Control-Allow-Origin", "*");
 		$result->setStatus($statusCode);
 		return $result;
 	}