Fix case of monitored service in startplasma's shutdown

Startplasma monitors ksmserver and tears down the session if it goes
away, to match previous behaviour and as some lockscreen bypass
protection.

When we teardown our new binary plasma-shutdown appears, runs scripts
and makes the final shutdown call. ksmserver could gracefully quit in
the meantime, so startplasma guarded this case and waited till both
names exited. However it contains a really stupid typo.

BUG: 422870

startkde/startplasma.cpp

@@ -384,7 +384,7 @@ bool startPlasmaSession(bool wayland)
     // We want to exit when both ksmserver and plasma-session-shutdown have finished
     // This also closes if ksmserver crashes unexpectedly, as in those cases plasma-shutdown is not running
     serviceWatcher.addWatchedService(QStringLiteral("org.kde.ksmserver"));
-    serviceWatcher.addWatchedService(QStringLiteral("org.kde.shutdown"));
+    serviceWatcher.addWatchedService(QStringLiteral("org.kde.Shutdown"));
     serviceWatcher.setWatchMode(QDBusServiceWatcher::WatchForUnregistration);
 
     QObject::connect(&startPlasmaSession, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished), [&rc, &e](int exitCode, QProcess::ExitStatus) {