chore(deps): update k8s.gcr.io/ingress-nginx/controller docker tag to v1.12.3

Author: renovate[bot]

configure/ingress-nginx/mandatory.yaml

@@ -206,7 +206,7 @@ spec:
         kubernetes.io/os: linux
       containers:
         - name: nginx-ingress-controller
-          image: k8s.gcr.io/ingress-nginx/controller:v1.2.0@sha256:d8196e3bc1e72547c5dec66d6556c0ff92a23f6d0919b206be170bc90d5f9185
+          image: k8s.gcr.io/ingress-nginx/controller:v1.12.3@sha256:ac444cd9515af325ba577b596fe4f27a34be1aa330538e8b317ad9d6c8fb94ee
           terminationMessagePolicy: FallbackToLogsOnError
           args:
             - /nginx-ingress-controller