Revert "k/ingress-nginx: use PROXY protocol"

This reverts commit 5131134c1d.

Well, that was a rather disappointing result. Turns out, DigitalOcean
adds PROXY lines to _all_ connections. I suppose that's to be expected.
However, what wasn't expected, was that ingress-nginx would only be
capable of handling them for HTTP/S traffic, and not TCP passthrough.
For that reason, we actually can't enable PROXY without instead using a
sidecar to eat the PROXY line.

kustomizations/ingress-nginx/controller/resources.yaml

@@ -101,8 +101,6 @@ apiVersion: v1
 kind: Service
 metadata:
   name: ingress-nginx-controller
-  annotations:
-    service.beta.kubernetes.io/do-loadbalancer-enable-proxy-protocol: "true"
 spec:
   ports:
   - appProtocol: http

kustomizations/ingress-nginx/kustomization.yaml

@@ -15,7 +15,6 @@ configMapGenerator:
   literals:
   - allow-snippet-annotations=true
   - annotations-risk-level=Critical
-  - use-proxy-protocol=true
 replacements:
 - source:
     kind: Certificate