Missing error message if cover file ist too big

[LyricsLover]

@rexfox

So I think it´s not a real bug (who needs 20 MB cover files?!)

Cannot embed large size cover image(s) for FLAC

FLAC has a limitation of ~16MB because the length field of the metadata block can only hold numbers up to 24bit. I'm moving this to #bug-reports:no-bugs