Send TCP FIN after completion of our RTSP request

This allows servers to read until a FIN, just like we do on the client.

src/RtspConnection.c

@@ -267,6 +267,9 @@ static bool transactRtspMessageTcp(PRTSP_MESSAGE request, PRTSP_MESSAGE response
         goto Exit;
     }
 
+    // Notify the server that we're finished sending the request with a FIN
+    shutdown(sock, SHUT_WR);
+
     // Read the response until the server closes the connection
     offset = 0;
     responseBufferSize = 0;