This drops the shebang from all target files for /lib and
/etc/uci-defaults folders, as these are sourced and the shebang
is useless.
While at it, fix the executable flag on a few of these files.
This does not touch ar71xx, as this target is just used for
backporting now and applying cosmetic changes would just complicate
things.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
