in case curl is not present we cannot test

lib/util.php

@@ -528,6 +528,10 @@ class OC_Util {
 	 *
 	 */
 	public static function isWebDAVWorking() {
+        if (!function_exists('curl_init')) {
+            return;
+        }
+
 		$settings = array(
 			'baseUri' => OC_Helper::linkToRemote('webdav'),
 		);