Changes:
- Remove first line (headline) previously parsed as gateway
- Delete leading whitespaces for netif correctly (regex
  "\\[" changed to "\\[ *")
- Remove netif whitespaces first, so they are not changed to
  "false"
- Include trailing whitespace in regex for selection marker
- Remove useless replacement "  " to " "

This is designed to support BATMAN compatibility version 14 AND 15

Signed-off-by: Adrian Schmutzler <[email protected]>
Tested-by: Adrian Schmutzler <[email protected]>
Reviewed-by: Tim Niemeyer <[email protected]>