netcfg hangs during preseeded static network installation

[Nick Minkler]

I'm building a preseeded ISO of 14.04 Trusty Tahr and have set dhcp_timeout to 1, along with disabling autoconfig, then setting and accepting a static IP. after this is completed netcfg appears to halt for 30 seconds to 1 minute attempting to reach the gateway. I see 1 ARP request to the gateway in the logs every second, and then after it tries doing this over and over it finally continues install.

We were previously using Maverick, and this lockup did not occur if the gateway was unreachable. There should be a configurable timeout option for this to prevent lockups, or if the system is configured statically it shouldn't even be attempting these lookups if that's possible.