/lib/functions.sh was executable for no obvious reason and its
execute property was even checked in package-ipkg.mk just to
source it afterwards.
Remove the execute bit and shebang as this is clearly a library.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Reviewed-by: Philip Prindeville <philipp@redfish-solutions.com>