proxy-protocol flag needs a new test

[johndietz]

proxy-protocol documentation:
https://www.civo.com/docs/kubernetes/load-balancers#proxy-protocol

A load balancer end to end test was recently removed due to its functionality having been replaced with the proxy-protocol flag. This issue is being created to track the need for this additional e2e test, per the discussion in the following PR.
#37 (comment)