grml-network: Fix obsolete nmap command line options

grml-network: Fix obsolete nmap command line options

host_timeout and max_rtt_timeout have been deprecated and undocumented
aliases for host-timeout and max-rtt-timeout.

The options have been removed from nmap in v7.70.
See: https://github.com/nmap/nmap/commit/23d95f5

While at it also use seconds instead of 'ms'. Quoting nmap(1):

  TIMING AND PERFORMANCE:
    Options which take <time> are in seconds, or append 'ms' (milliseconds),
    's' (seconds), 'm' (minutes), or 'h' (hours) to the value (e.g. 30m).

Closes: grml/grml-network#6