Pass v4 info to the right endpoint

src/Discord.Net/API/Client/Rest/Gateway.cs

@@ -6,7 +6,7 @@ namespace Discord.API.Client.Rest
     public class GatewayRequest : IRestRequest<GatewayResponse>
     {
         string IRestRequest.Method => "GET";
-        string IRestRequest.Endpoint => $"gateway?encoding=json&v=4";
+        string IRestRequest.Endpoint => $"gateway";
         object IRestRequest.Payload => null;
     }
 

src/Discord.Net/Net/WebSockets/GatewaySocket.cs

@@ -43,7 +43,8 @@ namespace Discord.Net.WebSockets
             //Token = rest.Token;
 
             var gatewayResponse = await rest.Send(new GatewayRequest()).ConfigureAwait(false);
-            Logger.Verbose($"Login successful, gateway: {gatewayResponse.Url}");
+            string url = $"{gatewayResponse.Url}?encoding=json&v=4";
+            Logger.Verbose($"Login successful, gateway: {url}");
 
             Host = gatewayResponse.Url;
             await BeginConnect(parentCancelToken).ConfigureAwait(false);