Create interfaces before processing the hostname.if file in ifstart().

Create interfaces before processing the hostname.if file in ifstart().

This ensures, that IPv6 is configured for dynamically created network
interfaces like 'vlan' which would otherwise not yet exist at the time
parse_hn_line() checks for IPv6 capability of an interface before
applying the inet6 configuration from the hostname.if.

Found out, tested and OK naddy