40network: fixup static network configuration

The static network configuration was broken; the 'gateway' was
written as the complete 'ip' command line, but simply sourced
later on.

The patch fixes the gateway registration that the '.gw' file
holds entire 'ip route' command lines, which just needs to
be evaluated later on.

Signed-off-by: Hannes Reinecke <hare@suse.de>