[extractor/redge] try to follow redir on nvr, ignore nvr format if invalid

yt_dlp/extractor/redge.py

@@ -1,4 +1,5 @@
 from .common import InfoExtractor
+from ..networking import HEADRequest
 from ..utils import (
     float_or_none,
     int_or_none,
@@ -100,8 +101,12 @@ class RedCDNLivxIE(InfoExtractor):
             ism_doc, ism_urlh = ism_res
             formats, _ = self._parse_ism_formats_and_subtitles(ism_doc, ism_urlh.url, 'ss')
 
+        nvr_urlh = self._request_webpage(
+            HEADRequest(livx_mode('nvr')), video_id, 'Follow flv file redirect', fatal=False,
+            expected_status=lambda _: True)
+        if nvr_urlh and nvr_urlh.getcode() == 200:
             formats.append({
-            'url': livx_mode('nvr'),
+                'url': nvr_urlh.url,
                 'ext': 'flv',
                 'format_id': 'direct-0',
                 'preference': -1,   # might be slow

yt_dlp/extractor/sejmpl.py

@@ -168,9 +168,9 @@ class SejmIE(InfoExtractor):
                 return
             file = f'https:{file}' if file.startswith('//') else file
             if not legacy_file:
-                update_url_query(file, {'startTime': start_time})
+                file = update_url_query(file, {'startTime': start_time})
                 if stop_time is not None:
-                    update_url_query(file, {'stopTime': stop_time})
+                    file = update_url_query(file, {'stopTime': stop_time})
                 stream_id = self._search_regex(r'/o2/sejm/([^/]+)/[^./]+\.livx', file, 'stream id')
             common_info = {
                 'url': file,