[downloader/niconico] Pass custom headers (#1063)

Closes #1057
Authored by: nao20010128nao

yt_dlp/downloader/niconico.py

@@ -6,7 +6,7 @@ import threading
 from .common import FileDownloader
 from ..downloader import get_suitable_downloader
 from ..extractor.niconico import NiconicoIE
-from ..compat import compat_urllib_request
+from ..utils import sanitized_Request
 
 
 class NiconicoDmcFD(FileDownloader):
@@ -29,9 +29,11 @@ class NiconicoDmcFD(FileDownloader):
         heartbeat_data = heartbeat_info_dict['data'].encode()
         heartbeat_interval = heartbeat_info_dict.get('interval', 30)
 
+        request = sanitized_Request(heartbeat_url, heartbeat_data)
+
         def heartbeat():
             try:
-                compat_urllib_request.urlopen(url=heartbeat_url, data=heartbeat_data)
+                self.ydl.urlopen(request).read()
             except Exception:
                 self.to_screen('[%s] Heartbeat failed' % self.FD_NAME)