[helpers/xclipboradsync] Ensure that KWayland::Client connects through the passed fd

One needs to call ConnectionThread::setSocketFd in order to not have it
connect through the normal socket.

As WAYLAND_SOCKET is set the implementation would call the correct
functionality anyway. This change only ensures that no wrong debug
message gets logged.

helpers/xclipboardsync/waylandclipboard.cpp

@@ -44,6 +44,7 @@ WaylandClipboard::WaylandClipboard(QObject *parent)
     , m_thread(new QThread)
     , m_connectionThread(new ConnectionThread)
 {
+    m_connectionThread->setSocketFd(qgetenv("WAYLAND_SOCKET").toInt());
     m_connectionThread->moveToThread(m_thread);
     m_thread->start();