Fix setBuffer of the OutputMessage class

src/framework/net/outputmessage.cpp

@@ -38,11 +38,11 @@ void OutputMessage::reset()
 void OutputMessage::setBuffer(const std::string& buffer)
 {
     int len = buffer.size();
-    checkWrite(MAX_HEADER_SIZE + len);
-    memcpy(m_buffer + MAX_HEADER_SIZE, buffer.c_str(), len);
-    m_writePos = MAX_HEADER_SIZE;
-    m_headerPos = MAX_HEADER_SIZE;
-    m_messageSize = len;
+    reset();
+    checkWrite(len);
+    memcpy((char*)(m_buffer + m_writePos), buffer.c_str(), len);
+    m_writePos += len;
+    m_messageSize += len;
 }
 
 void OutputMessage::addU8(uint8 value)