veyron/lib/netconfig: Fix build on Mac.
veyron/lib/netconfig: Fix build on Mac.

(Updates https://veyron-review.googlesource.com/#/c/5499)

Change-Id: I39c91fd07b0bb3d0485f41a4d720b7c9c698d295

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref