Remove i8

It's better to use types from the standard library.

source/network/NetFileTransfer.cpp

@@ -156,7 +156,7 @@ void CNetFileTransferer::StartTask(RequestType requestType, std::function<void(s
 	m_FileReceiveTasks.emplace(requestID, AsyncFileReceiveTask{std::move(task)});
 
 	CFileTransferRequestMessage request;
-	request.m_RequestType = static_cast<i8>(requestType);
+	request.m_RequestType = static_cast<std::int8_t>(requestType);
 	request.m_RequestID = requestID;
 	m_SendMessage(&request);
 }