args4j: update runbundles in bndrun files

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
flac2mp3: treat the scan path as a normal relative path

Not as a relative path from the flac basedir.
We already check that it's below the flac basedir a little below

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>