Remove 'NULL' insertions at nowplaying
Remove 'NULL' insertions at nowplaying

An earlier commit that tried to prevent Album.name = '' instead produces
Album.name = 'NULL' and also Track.mbid = 'NULL' because of incorrect
quoting of $album and $mbid vars in nowplaying/1.2/index.php

This commit fixes for the problem but we should add functions to
scrobbleutils.php for submissions/1.2/index.php and
nowplaying/1.2/index.php to use when trimming and quoting strings so
they dont diverge.

foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm,foocorp/gnu-fm