Fix multiple handling

Core/GeneralHandler.cs

@@ -29,7 +29,7 @@ namespace Kruzya.TelegramBot.Core
 
         [HandleEverything]
         [Priority(-10)]
-        public async Task Listener()
+        public async Task<bool> Listener()
         {
             foreach (var message in new Message[] {RawUpdate.Message, RawUpdate.EditedMessage, RawUpdate.ChannelPost, RawUpdate.EditedChannelPost})
             {
@@ -40,6 +40,8 @@ namespace Kruzya.TelegramBot.Core
 
                 await VerifyChatPair(message);
             }
+
+            return true;
         }
 
         public async Task VerifyChatPair(Message message)