MDL-45619 repository: Don't allow repository_recent to be uninstalled

We have tests that depends on it and it
is a simple repo that can just be disabled.

lib/classes/plugininfo/repository.php

@@ -73,7 +73,7 @@ public static function get_manage_url() {
      * @return boolean
      */
     public function is_uninstall_allowed() {
-        if ($this->name === 'upload' || $this->name === 'coursefiles' || $this->name === 'user') {
+        if ($this->name === 'upload' || $this->name === 'coursefiles' || $this->name === 'user' || $this->name === 'recent') {
             return false;
         } else {
             return true;