fix a issue where cleaning a patha s a url, a=chris

diff --git a/src/controllers/FetchController.php b/src/controllers/FetchController.php
index 8fbeec4ba..0e890607b 100755
--- a/src/controllers/FetchController.php
+++ b/src/controllers/FetchController.php
@@ -80,7 +80,7 @@ class FetchController extends Controller implements CrawlConstants
             (isset($_REQUEST['machine_uri']))) {
             $robot_table[$this->clean($_REQUEST['robot_instance'], "string")] =
                 [$_SERVER['REMOTE_ADDR'],
-                $this->clean($_REQUEST['machine_uri'], "web-url"),
+                $this->clean($_REQUEST['machine_uri'], "string"),
                 time()];
             file_put_contents($robot_table_name, serialize($robot_table),
                 LOCK_EX);