Kit: Fix possible crash

Fix crash in KitOptionsPage related to setting the default kit

Task-number: QTCREATORBUG-14053
Change-Id: Icf10b2596afa0a3b871aca0685a6f7d3a59ab022
Reviewed-by: Daniel Teske <daniel.teske@theqtcompany.com>

src/plugins/projectexplorer/kitmodel.cpp

@@ -246,6 +246,9 @@ void KitModel::markForRemoval(Kit *k)
         setDefaultNode(static_cast<KitNode *>(newDefault));
     }
 
+    if (node == m_defaultNode)
+        setDefaultNode(findItemAtLevel<KitNode *>(2, [node](KitNode *kn) { return kn != node; }));
+
     removeItem(node);
     if (node->widget->configures(0))
         delete node;
@@ -353,8 +356,9 @@ void KitModel::removeKit(Kit *k)
         }
     }
 
-    if (m_defaultNode == node)
-        m_defaultNode = 0;
+    if (node == m_defaultNode)
+        setDefaultNode(findItemAtLevel<KitNode *>(2, [node](KitNode *kn) { return kn != node; }));
+
     removeItem(node);
     delete node;