avoid calling GetHeight() on non-IsOk() icons

probably fixes #3837

src/slic3r/GUI/ObjectDataViewModel.cpp

@@ -1710,10 +1710,11 @@ bool BitmapChoiceRenderer::Render(wxRect rect, wxDC* dc, int state)
     {
         dc->DrawBitmap(icon, rect.x, rect.y + (rect.height - icon.GetHeight()) / 2);
         xoffset = icon.GetWidth() + 4;
+
+        if (rect.height==0)
+          rect.height= icon.GetHeight();
     }
 
-    if (rect.height==0)
-        rect.height= icon.GetHeight();
     RenderText(m_value.GetText(), xoffset, rect, dc, state);
 
     return true;