Can't build with Qt5 < 5.10

[oldherl]

This overload of QMetaObject::invokeMethod was introduced in Qt 5.10, so it can't be built with Qt5 before that.
Should update minimum Qt requirement in CMakeList or change these back to old style.

fcitx5-qt/qt5/platforminputcontext/qfcitxplatforminputcontext.cpp

Lines 257 to 265 in 94c8644

	// Input context may be created without QApplication with wayland, defer it
	// to event loop to ensure event dispatcher is avaiable.
	QMetaObject::invokeMethod(
	this,
	[this]() {
	watcher_->watch();
	fcitx4Watcher_->watch();
	},
	Qt::QueuedConnection);

fcitx5-qt/qt5/platforminputcontext/qfcitxplatforminputcontext.cpp

Lines 530 to 539 in 94c8644

	QMetaObject::invokeMethod(
	this,
	[this, window = QPointer<QWindow>(lastWindow_)]() {
	if (window != lastWindow_) {
	return;
	}
	update(Qt::ImHints | Qt::ImEnabled);
	updateCursorRect();
	},
	Qt::QueuedConnection);