net-mgmt/bandwhich: fix build after r551268

Apparently the build fails (I can't replicate the issue on my builders)

> Configuring for bandwhich-0.19.0

Updating git repository `https://github.com/tailhook/resolv-conf`

warning: spurious network error (2 tries remaining): failed to resolve address for github.com: Name does not resolve; class=Net (12)
warning: spurious network error (1 tries remaining): failed to resolve address for github.com: Name does not resolve; class=Net (12)
error: failed to resolve patches for https://github.com/rust-lang/crates.io-index

Caused by:

failed to load source for dependency `resolv-conf`

PR: 249571
Reported by: olgeni
Approved by: portmgr (implicit, build fix)