Update CaddyFile to use the links

docker/Caddyfile

@@ -5,15 +5,15 @@
 
 # Dashboard
 https://dashboard.NETMAKER_BASE_DOMAIN {
-    reverse_proxy http://127.0.0.1:8082
+    reverse_proxy http://ui:80
 }
 
 # API
 https://api.NETMAKER_BASE_DOMAIN {
-    reverse_proxy http://127.0.0.1:8081
+    reverse_proxy http://api:8081
 }
 
 # gRPC
 https://grpc.NETMAKER_BASE_DOMAIN {
-    reverse_proxy h2c://127.0.0.1:50051
-}
+    reverse_proxy h2c://api:50051
+}