change artwork provider to fanart.tv

[nopoz]

Changes artwork provider to fanart.tv

Fixes #3207

last.fm has changed their API so artwork can no longer be retrieved. Only data can be pulled.

When the age of the existing artwork cache expires, headphones tries to grab new artwork from last.fm - which it can't. This has resulted in headphones instances hammering the last.fm API and reaching the API query limit. This change should reduce the amount of API calls to last.fm.

[nopoz]

In order for headphones to pull new artwork for artists/albums that already exist in your db, you might need to clear the headphones.db of existing thumb and album urls, and clear the cache/artwork/ directory of all old artwork files.

1. stop headphones daemon

2. open your database:

sqlite3 headphones.db

3. while in sqlite interactive mode, set all artwork column data to null (remove it)

update albums set ArtworkURL=null;
update albums set ThumbURL=null;
update artists set ArtworkURL=null;
update artists set ThumbURL=null;

4. delete all old artwork files in the cache/artwork/ directory

5. start headphones daemon back up

Or just delete your headphones.db file and start from scratch - up to you!