[mythtv] Mythweb fails to detect MythMusic properly

[Bryan Mayland]

in /mythweb/modules/music/init.php:
// First, we should check to see that MythMusic is configured.
    $has_music = $db->query_col('SELECT COUNT(*) FROM musicmetadata');

If the user does not have MythMusic installed, there will be no 
musicmetadata table at all.  The query will fail in db.php with:
*Fatal Error* at /mythweb/includes/db.php, line 314:
SQL Error: Table 'mythconverg.musicmetadata' doesn't exist [#1146]