ubihealthd: Add option -h/--help

ubihealthd: Add option -h/--help

Using '?' as option did not work, and would be strange to pass anyway,
because it's a glob char for the shell and you would have to escape it
like ./ubihealthd -\? … use the more common -h/--help instead.

Note: this does not touch the output, just changes the options itself.

Signed-off-by: Alexander Dahl <post@lespocky.de>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>