Ensure that combobox editor used by wxGrid is tall enough.

Set the rectangle of wxGridCellChoiceEditor to be at least as tall as the best
(i.e. minimal) wxComboBox size because otherwise the control can be unusable.

Closes #13818.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70693 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/grideditors.h

@@ -295,6 +295,8 @@ public:
                         wxWindowID id,
                         wxEvtHandler* evtHandler);
 
+    virtual void SetSize(const wxRect& rect);
+
     virtual void PaintBackground(const wxRect& rectCell, wxGridCellAttr *attr);
 
     virtual void BeginEdit(int row, int col, wxGrid* grid);