Fix getting the old approximate diameter
Fix getting the old approximate diameter

The properties.approximate_diameter gets updated later via signals, so at this point it's not correct yet.

Contributes to issue CURA-2822.

Curahelper/Cura,fieldOfView/Cura,Curahelper/Cura,fieldOfView/Cura,ynotstartups/Wanhao,ynotstartups/Wanhao