[kcmkwin/rules] Disable detect button on Wayland

Summary:
The detect functionality is still extremely bound to X11 and results in
a crash when clicked. Thus it's better to disable it completely in 5.12
on Wayland.

Test Plan: Button disabled on Wayland, enabled on X11

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D10642

kcmkwin/kwinrules/ruleswidget.cpp

@@ -56,6 +56,8 @@ RulesWidget::RulesWidget(QWidget* parent)
 {
     Q_UNUSED(parent);
     setupUi(this);
+    detect->setVisible(KWindowSystem::isPlatformX11());
+    detection_delay->setVisible(KWindowSystem::isPlatformX11());
     QRegularExpressionValidator* validator = new QRegularExpressionValidator(QRegularExpression("[0-9\\-+,xX:]*"), this);
     maxsize->setValidator(validator);
     minsize->setValidator(validator);