[theplatform] Handle protocolless feed URLs (Closes #7532)

youtube_dl/extractor/theplatform.py

@@ -187,7 +187,8 @@ class ThePlatformIE(ThePlatformBaseIE):
             # Seems there's no pattern for the interested script filename, so
             # I try one by one
             for script in reversed(scripts):
-                feed_script = self._download_webpage(script, video_id, 'Downloading feed script')
+                feed_script = self._download_webpage(
+                    self._proto_relative_url(script, 'http:'), video_id, 'Downloading feed script')
                 feed_id = self._search_regex(r'defaultFeedId\s*:\s*"([^"]+)"', feed_script, 'default feed id', default=None)
                 if feed_id is not None:
                     break