plasma: remove redundant method

the window manager should probably not be changed if there are active
applications (i.e. until the next login in most cases) to begin with

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>

kcontrol/componentchooser/componentchooserwm.cpp

@@ -134,8 +134,6 @@ bool CfgWm::saveAndConfirm()
     if (tryWmLaunch()) {
         oldwm = currentWm();
         cfg.sync();
-        QDBusInterface plasma("org.kde.plasma-desktop", "/App", "local.PlasmaApp");
-        plasma.call(QDBus::NoBlock, "wmChanged");
         KMessageBox::information(
             window(),
             i18n("A new window manager is running.\n"

plasma/shells/plasma-desktop/dbus/org.kde.plasma.App.xml

@@ -28,7 +28,5 @@
       <arg name="confirm" type="i" direction="in"/>
       <arg name="sdtype" type="i" direction="in"/>
     </method>
-    <method name="wmChanged">
-    </method>
   </interface>
 </node>

plasma/shells/plasma-desktop/plasmaapp.cpp

@@ -1157,11 +1157,6 @@ void PlasmaApp::logout(int confirm, int sdtype)
     m_dialogActive = false;
 }
 
-void PlasmaApp::wmChanged()
-{
-    // changing the window manager happens from the KCM, currently nothing to do when that happens
-}
-
 void PlasmaApp::captureDesktop()
 {
     KToolInvocation::self()->kdeinitExec("ksnapshot", QStringList() << "--fullscreen");

plasma/shells/plasma-desktop/plasmaapp.h

@@ -108,7 +108,6 @@ public Q_SLOTS:
     void suspendStartup(const QString &app);
     void resumeStartup(const QString &app);
     void logout(int confirm, int sdtype);
-    void wmChanged();
 
 protected:
 #ifdef Q_WS_X11