Added the parameter business_connection_id to the method stopPoll

Author: mircoianese

library/src/main/java/com/pengrad/telegrambot/request/StopPoll.java

@@ -17,4 +17,8 @@ public StopPoll(Object chatId, int messageId) {
     public StopPoll replyMarkup(Keyboard replyMarkup) {
         return add("reply_markup", replyMarkup);
     }
+
+    public StopPoll businessConnectionId(String businessConnectionId) {
+        return add("business_connection_id", businessConnectionId);
+    }
 }