DHCP client: increase 'recvTimeout'
DHCP client: increase 'recvTimeout'

Two seconds is too short.  Some DHCP servers take longer to respond,
usually because they send out ARP requests for the address about to be
assigned.

Reported-by: Arjan van Vught <06b243b7afa4a3f757e398f5f6dd8dcce289f886@gmail.com>

robert-w-gries/xinu,robert-w-gries/xinu,ZeroTau/xinu,robert-w-gries/xinu,ZeroTau/xinu,ZeroTau/xinu