Alert user when limit is reached.

When the user tries to create more configurations than are allow an
alert will pop up.

server.go

@@ -596,7 +596,21 @@ func (s *Server) CreateClient(w http.ResponseWriter, r *http.Request, ps httprou
 	if *maxNumberClientConfig > 0 {
 		if len(c.Clients) >= *maxNumberClientConfig {
 			log.Error(fmt.Errorf("user %q have too many configs", c.Name))
+
+			e := struct {
+				Error string
+			}{
+				Error: "Max number of configs: " + strconv.Itoa(*maxNumberClientConfig),
+			}
+
+			j, err := json.Marshal(e)
+			if err != nil {
+				log.Error(err)
+				return
+			}
+
 			w.WriteHeader(http.StatusTooManyRequests)
+			fmt.Fprintf(w, string(j))
 			return
 		}
 	}

ui/src/Clients.svelte

@@ -17,12 +17,22 @@
   async function handleNewClick(event) {
     const res = await fetch(clientsUrl, {
       method: "POST",
-    });
-    let newClient = await res.json();
-    console.log("New client added", newClient);
+    })
+      .then(response => {
+        return response.json()
+    })
+    .then(data => {
+      if (typeof data.Error != "undefined") {
+          console.log(data.Error);
+          alert(data.Error);
+    } else {
+        console.log("New client added", data);
+    }
+  });
     await getClients();
   }
 
+
 	onMount(getClients);
 </script>