TargetSetupPage: Ignore changes while ProjectImporter is updating

This causes the same kit to be processed repeatedly, which should not
cause harm, but waste CPU cycles.

Change-Id: Ie42272aacec6d8350398b65973570282c0c8d287
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/projectexplorer/targetsetuppage.cpp

@@ -344,12 +344,12 @@ void TargetSetupPage::handleKitAddition(Kit *k)
 
 void TargetSetupPage::handleKitRemoval(Kit *k)
 {
-    if (m_importer)
-        m_importer->cleanupKit(k);
-
     if (isUpdating())
         return;
 
+    if (m_importer)
+        m_importer->cleanupKit(k);
+
     removeWidget(k);
     updateVisibility();
 }