Valgrind: Make socket parentless when passed to Parser

Otherwise, when the socket is a child of QTcpServer,
it may be deleted together with a server, while it's
still held in Parser instance.

Change-Id: I600e9cef1268ffc93e1e86d317e087df8b4d70cb
Reviewed-by: hjk <hjk@qt.io>

src/plugins/valgrind/xmlprotocol/parser.cpp

@@ -761,6 +761,7 @@ void Parser::setSocket(QAbstractSocket *socket)
     QTC_ASSERT(socket, return);
     QTC_ASSERT(socket->isOpen(), return);
     QTC_ASSERT(!isRunning(), return);
+    socket->setParent(nullptr); // Don't delete it together with parent QTcpServer anymore.
     d->m_socket.reset(socket);
 }