Replace tabs with spaces in metadata

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Play action triggers I'm feeling lucky mix

When no music is paused and the Listen now page is loaded, play action
triggers I'm feeling lucky mix instead of doing nothing.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>