Fix loading if KActivities is in state NotRunning

Summary:
Used to work, then patch f7ef6ee87b
changed it.

Docs above edited code say:
"it is valid for KAMD to not be running."

This fixes that but keeps the objective of patch f7ef6ee, of delaying
load() if we're still loading KAMD.

Test Plan:

Reviewers:
#plasma

Subscribers:

shell/shellcorona.cpp

@@ -302,7 +302,7 @@ void ShellCorona::setShell(const QString &shell)
 
     connect(m_activityController, &KActivities::Controller::serviceStatusChanged, this, &ShellCorona::load, Qt::UniqueConnection);
 
-    if (m_activityController->serviceStatus() == KActivities::Controller::Running) {
+    if (m_activityController->serviceStatus() != KActivities::Controller::Unknown) {
         load();
     }
 }
@@ -332,7 +332,7 @@ static QList<QScreen*> sortOutputs(const QList<QScreen*> &outputs)
 void ShellCorona::load()
 {
     if (m_shell.isEmpty() ||
-        m_activityController->serviceStatus() != KActivities::Controller::Running) {
+        m_activityController->serviceStatus() == KActivities::Controller::Unknown) {
         return;
     }