firefly-iii: Set instance label for Argo CD

Argo CD wants every resource managed by an application to have that
application's name as the value of the `app.kubernetes.io/instance`
label.

firefly-iii/ingress.yaml

@@ -13,9 +13,10 @@ metadata:
     nginx.ingress.kubernetes.io/auth-method: GET
     nginx.ingress.kubernetes.io/auth-url: http://authelia.authelia.svc.cluster.local:9091/api/verify
     nginx.ingress.kubernetes.io/auth-signin: https://auth.pyrocufflink.blue/?rm=$request_method
-    nginx.ingress.kubernetes.io/auth-response-headers: Remote-User,Remote-Name,Remote-Groups,Remote-Email
     nginx.ingress.kubernetes.io/auth-snippet: |
       proxy_set_header X-Forwarded-Method $request_method;
+    nginx.ingress.kubernetes.io/configuration-snippet: |
+      proxy_set_header Remote-User dustin;
 spec:
   ingressClassName: nginx
   tls: