QmlDesigner: Fix crash for master document handling

Happens for dragging a list view in the document.

Change-Id: Id8d00fc880789a0e5e85d455850bb1ec3eaac434
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

src/plugins/qmldesigner/components/integration/componentview.cpp

@@ -126,7 +126,7 @@ void ComponentView::addMasterDocument()
 
 void ComponentView::removeMasterDocument()
 {
-    m_standardItemModel->removeColumn(indexOfMaster());
+    m_standardItemModel->removeRow(indexOfMaster());
 }
 
 QString ComponentView::descriptionForNode(const ModelNode &node) const