Fixed segfault when pressing play on folder

When you press "play" on a folder instead of an item XBMC's API will send and event like this:

{"jsonrpc":"2.0","method":"Player.OnPlay","params":{"data":{"item":{"type":"unknown"},"player":{"playerid":0,"speed":1}},"sender":"xbmc"}}

This would segfault current code as 'title' is NULL.