Explicitly set the ingress name to gitea-ingress

The old config was generating a separate nginx ingress instead of
attaching the HTTP challenge URL to our existing ingress (gitea-ingress)

kubernetes/letsencrypt-production.yaml

@@ -12,8 +12,9 @@ spec:
     privateKeySecretRef:
       # Secret resource used to store the account's private key.
       name: letsencrypt-production-account-key
-    # Add a single challenge solver, HTTP01 using nginx
+    # Add a single challenge solver, HTTP01 using the gitea-ingress
+    # https://docs.cert-manager.io/en/latest/reference/api-docs/index.html#acmechallengesolverhttp01ingress-v1alpha1
     solvers:
     - http01:
         ingress:
-          class: nginx
+          name: gitea-ingress

kubernetes/letsencrypt-staging.yaml

@@ -4,7 +4,6 @@ metadata:
   name: letsencrypt-staging
 spec:
   acme:
-    # You must replace this email address with your own.
     # Let's Encrypt will use this to contact you about expiring
     # certificates, and issues related to your account.
     email: ops@kosmos.org
@@ -12,8 +11,9 @@ spec:
     privateKeySecretRef:
       # Secret resource used to store the account's private key.
       name: letsencrypt-staging-account-key
-    # Add a single challenge solver, HTTP01 using nginx
+    # Add a single challenge solver, HTTP01 using the gitea-ingress
+    # https://docs.cert-manager.io/en/latest/reference/api-docs/index.html#acmechallengesolverhttp01ingress-v1alpha1
     solvers:
     - http01:
         ingress:
-          class: nginx
+          name: gitea-ingress