Readded 502 handling

src/Discord.Net/Net/Queue/RequestQueueBucket.cs

@@ -1,6 +1,7 @@
 #pragma warning disable CS4014
 using System;
 using System.IO;
+using System.Net;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -68,6 +69,10 @@ namespace Discord.Net.Queue
                         //We have all our semaphores, send the request
                         return await request.SendAsync().ConfigureAwait(false);
                     }
+                    catch (HttpException ex) when (ex.StatusCode == HttpStatusCode.BadGateway)
+                    {
+                        continue;
+                    }
                     catch (HttpRateLimitException ex)
                     {
                         Pause(ex.RetryAfterMilliseconds);

src/Discord.Net/Net/Rest/DefaultRestClient.cs

@@ -127,7 +127,8 @@ namespace Discord.Net.Rest
                     if (statusCode == 429)
                     {
                         //TODO: Include bucket info
-                        throw new HttpRateLimitException(int.Parse(response.Headers.GetValues("retry-after").First()));
+                        int retryAfterMillis = int.Parse(response.Headers.GetValues("retry-after").First());
+                        throw new HttpRateLimitException(retryAfterMillis);
                     }
 
                     string reason = null;