Fix type of local variable stopSock in RunMiniServer()

The variable is declared as SOCKET, but it is used to
store return value of int receive_from_stopSock(...).
The type was changed in the commit
4b47e6a51d by mistake.

upnp/src/genlib/miniserver/miniserver.c

@@ -377,7 +377,7 @@ static void RunMiniServer(
 	fd_set rdSet;
 	SOCKET maxMiniSock;
 	int ret = 0;
-	SOCKET stopSock = 0;
+	int stopSock = 0;
 
 	maxMiniSock = 0;
 	maxMiniSock = max(maxMiniSock, miniSock->miniServerSock4);