fix module test

app/modules/qbittorrent/__init__.py

@@ -43,10 +43,12 @@ class QbittorrentModule(_ModuleBase, _DownloaderBase):
     def stop(self):
         pass
 
-    def test(self) -> Tuple[bool, str]:
+    def test(self) -> Optional[Tuple[bool, str]]:
         """
         测试模块连接性
         """
+        if not self._servers:
+            return None
         for name, server in self._servers.items():
             if server.is_inactive():
                 server.reconnect()