Ingress NGINX: Promote NGINX v1.2.0.

Commit: kubernetes/ingress-nginx@521a80c
Job: https://prow.k8s.io/view/gs/kubernetes-ci-logs/logs/post-ingress-nginx-nginx/1878187545389436928
Build: https://storage.googleapis.com/kubernetes-ci-logs/logs/post-ingress-nginx-nginx/1878187545389436928/artifacts/build.log

Author: Gacko

registry.k8s.io/images/k8s-staging-ingress-nginx/images.yaml

@@ -221,6 +221,7 @@
     "sha256:73b4df804b128dc7aed9a769e17e9eaa70304895f26115c3d57e44e08ecc3685": ["v0.3.0"]
     "sha256:11ee0d0e3d063f1468f9a82958d57fa0718614fe10b676941f4dea0aef091faf": ["v1.0.0"]
     "sha256:43e04f78d7544010e2e86918faae1d15091995b7ef6e522f53cf3035ad814567": ["v1.1.0"]
+    "sha256:c4b3f79fb88eab2ac03bde5c6b8340ffad941e0fce0eaa797e98481683b3b5aa": ["v1.2.0"]
 
 # Ingress NGINX: Test Runner
 - name: e2e-test-runner