Fix not being able to download video behind login in format https://h…

…ost/Mediasite/Channel/channel_id/watch/resource_id

Maybe only works where the channel_id in the url == MediasiteChannelId

yt_dlp/extractor/mediasite.py

@@ -27,7 +27,7 @@
 class MediasiteIE(InfoExtractor):
     _VALID_URL = rf'''(?xi)https?://[^/]+/Mediasite/(?:Play
                                                        |Showcase/[^/#?]+/Presentation
-                                                       |Channel/[^/#?]+/watch
+                                                       |Channel/(?P<channel>[^/#?]+)/watch
                                                     )/(?P<id>{_ID_RE})(?P<query>\?[^#]+|)'''
     _EMBED_REGEX = [rf'(?xi)<iframe\b[^>]+\bsrc=(["\'])(?P<url>(?:(?:https?:)?//[^/]+)?/Mediasite/Play/{_ID_RE}(?:\?.*?)?)\1']
     _TESTS = [
@@ -260,6 +260,11 @@ def _real_extract(self, url):
         mobj = self._match_valid_url(url)
         resource_id = mobj.group('id')
         query = mobj.group('query')
+        channel = mobj.group('channel')
+
+        print (query)
+        if query == '':
+            query = '?Collection=' + channel
 
         webpage, urlh = self._download_webpage_handle(url, resource_id)  # XXX: add UrlReferrer?
         redirect_url = urlh.url