[mangoxo] change token message level to debug

The login page currently doesn't provide and require a login token
(logging in works without a token), so printing a warning during
each login is unnecessary.

gallery_dl/extractor/mangoxo.py

@@ -37,7 +37,7 @@ class MangoxoExtractor(Extractor):
         page = self.request(self.root + "/login/").text
         token = text.extract(page, 'id="loginToken" value="', '"')[0]
         if not token:
-            self.log.warning("failed to extract 'loginToken'")
+            self.log.debug("failed to extract 'loginToken'")
 
         url = self.root + "/login/loginxmm"
         headers = {