revert: remove incorrect /api ingress rule, frontend nginx handles /v1 proxy

chart/templates/ingress.yaml

@@ -19,13 +19,6 @@ spec:
     - host: {{ .Values.ingress.host }}
       http:
         paths:
-          - path: /api
-            pathType: Prefix
-            backend:
-              service:
-                name: {{ .Release.Name }}-backend
-                port:
-                  number: {{ .Values.backend.port }}
           - path: /
             pathType: Prefix
             backend: