fix protocol crash

src/framework/net/protocol.cpp

@@ -61,6 +61,7 @@ void Protocol::send(OutputMessage& outputMessage)
     outputMessage.addU16(messageSize);
 
     // send
+    if(m_connection)
         m_connection->write(outputMessage.getBuffer(), outputMessage.getMessageSize());
 }
 
@@ -68,6 +69,7 @@ void Protocol::recv()
 {
     m_inputMessage.reset();
 
+    if(m_connection)
         m_connection->read(InputMessage::HEADER_LENGTH, std::bind(&Protocol::internalRecvHeader, asProtocol(),  _1,  _2));
 }
 
@@ -80,6 +82,7 @@ void Protocol::internalRecvHeader(uint8* buffer, uint16 size)
     m_inputMessage.setMessageSize(dataSize);
 
     // schedule read for message data
+    if(m_connection)
         m_connection->read(dataSize, std::bind(&Protocol::internalRecvData, asProtocol(),  _1,  _2));
 }