[dtube] PEP 8 (#17455)

youtube_dl/extractor/dtube.py

@@ -59,7 +59,7 @@ class DTubeIE(InfoExtractor):
             try:
                 self.to_screen('%s: Checking %s video format URL' % (video_id, format_id))
                 self._downloader._opener.open(video_url, timeout=5).close()
-            except timeout as e:
+            except timeout:
                 self.to_screen(
                     '%s: %s URL is invalid, skipping' % (video_id, format_id))
                 continue