Crash on messages forwarded from chats

[pt300]

Telebot crashes when freeing updates object if one of the messages was a forward from a chat.

I traced the problem to line 488 in telebot-parser.c, which seems to be a mistake when copy pasting similar code.

telebot/src/telebot-parser.c

Lines 485 to 494 in c74d78d

	struct json_object *forward_from_chat = NULL;
	if (json_object_object_get_ex(obj, "forward_from_chat", &forward_from_chat))
	{
	msg->forward_from = malloc(sizeof(telebot_user_t));
	if (telebot_parser_get_chat(forward_from_chat, msg->forward_from_chat) != TELEBOT_ERROR_NONE)
	{
	ERR("Failed to get <forward from> from message object");
	TELEBOT_SAFE_FREE(msg->forward_from_chat);
	}
	}

It ought to be msg->forward_from_chat = malloc(sizeof(telebot_chat_t));.

This causes a bug in which msg->forward_from is overwritten with a pointer to uninitialized memory. This causes issues during freeing, as telebot_put_user sees non-null pointers and tries to free them. This causes memory corruption and an eventual crash.