[extractor/hidive] Fix cookie login when netrc is also given (#4447)

Closes #3336

Authored by: winterbird-code

yt_dlp/extractor/hidive.py

@@ -38,7 +38,9 @@ def _perform_login(self, username, password):
         webpage = self._download_webpage(self._LOGIN_URL, None)
         form = self._search_regex(
             r'(?s)<form[^>]+action="/account/login"[^>]*>(.+?)</form>',
-            webpage, 'login form')
+            webpage, 'login form', default=None)
+        if not form:  # logged in
+            return
         data = self._hidden_inputs(form)
         data.update({
             'Email': username,