Gui: fix property editor crash on recompute

The actual cause of crash in previous commit 80f70ff6 is
Document::recompute() allows aborting using Base::Sequence, which
uses QApplication::processEvent() to catch 'ESC' key press. This local
event loop causes premature deletion of the editor widget.

This patch moves handling of closeEditor before calling recompute().

src/Gui/propertyeditor/PropertyEditor.cpp

@@ -233,6 +233,8 @@ void PropertyEditor::onItemActivated ( const QModelIndex & index )
 
 void PropertyEditor::closeEditor (QWidget * editor, QAbstractItemDelegate::EndEditHint hint)
 {
+    QTreeView::closeEditor(editor, hint);
+
     if (autoupdate) {
         App::Document* doc = App::GetApplication().getActiveDocument();
         if (doc) {
@@ -249,8 +251,6 @@ void PropertyEditor::closeEditor (QWidget * editor, QAbstractItemDelegate::EndEd
     QModelIndex indexSaved = currentIndex();
     FC_LOG("index saved " << indexSaved.row() << ", " << indexSaved.column());
 
-    QTreeView::closeEditor(editor, hint);
-
     QModelIndex lastIndex;
     while(this->state()!=EditingState) {
         QModelIndex index;