LGTM: [skip ci] fix: Empty branch of conditional

An empty block after a conditional can be a sign of an omission and can decrease maintainability of the code.
Such blocks should contain an explanatory comment to aid future maintainers.

src/Mod/Part/Gui/ViewProviderExt.cpp

@@ -978,6 +978,7 @@ bool ViewProviderPartExt::setEdit(int ModNum)
 void ViewProviderPartExt::unsetEdit(int ModNum)
 {
     if (ModNum == ViewProvider::Color) {
+        // Do nothing here
     }
     else {
         Gui::ViewProviderGeometryObject::unsetEdit(ModNum);