[YouTube] Now music mixes can be treated as normal mixes

Using a playlist extractor on them would result in "Unviewable playlist" errors

Author: Stypox

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelper.java

@@ -388,8 +388,7 @@ public static OffsetDateTime parseDateFrom(final String textualUploadDate)
      * @return Whether given id belongs to a YouTube Mix
      */
     public static boolean isYoutubeMixId(@Nonnull final String playlistId) {
-        return playlistId.startsWith("RD")
-                && !isYoutubeMusicMixId(playlistId);
+        return playlistId.startsWith("RD");
     }
 
     /**

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeService.java

@@ -110,8 +110,7 @@ public ChannelExtractor getChannelExtractor(final ListLinkHandler linkHandler) {
 
     @Override
     public PlaylistExtractor getPlaylistExtractor(final ListLinkHandler linkHandler) {
-        if (YoutubeParsingHelper.isYoutubeMixId(linkHandler.getId())
-                && !YoutubeParsingHelper.isYoutubeMusicMixId(linkHandler.getId())) {
+        if (YoutubeParsingHelper.isYoutubeMixId(linkHandler.getId())) {
             return new YoutubeMixPlaylistExtractor(this, linkHandler);
         } else {
             return new YoutubePlaylistExtractor(this, linkHandler);