[youtube] Correct a minor regex typo

youtube_dl/extractor/youtube.py

@@ -137,7 +137,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                          (?:https?://|//)?                                    # http(s):// or protocol-independent URL (optional)
                          (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/|
                             (?:www\.)?deturl\.com/www\.youtube\.com/|
-                            (?:www\.)?pwnyoutube\.com|
+                            (?:www\.)?pwnyoutube\.com/|
                             tube\.majestyc\.net/|
                             youtube\.googleapis\.com/)                        # the various hostnames, with wildcard subdomains
                          (?:.*?\#/)?                                          # handle anchor (#/) redirect urls