Fixes the song disk bug

This commit fixes the song disk bug, because when you opens the inventory it doesn't gives to you the real disk name, that occurs because the packet wasn't giving the item category of song_disk that's 8, it was giving the category of default that's 1. And the extra field wasn't filled with the song id, for fixing that I got the song id from extraData, that's a array of strings, the latest item of this array is the songId, then I inserted it in the extra field.

Before:

(This name was appearing for any disk song)

After:

(Real disk song names)

And now nitro is parsing the packet correctly:

Being the category 8, because is a song_disk, and the extra is the songId