Delete the property setter on uninstall

[nliechti]

The property setter that overrides the available print pdf_generator is set to a wrong value on v16.

[nliechti]

@maharshivpatel I know this app is not gonna be maintained for long. But the current uninstall behaviour of the print_designer breaks all updated Instances to v16 as it effectively overwrites the pdf_renderer option to just wkhtmltopdf even though chrome should be available.

[nliechti]

@NagariaHussain Can you maybe look at this and give it a go if its ok? I think this will cost a lot of users a lot of time to find the problem after they uninstalled the Print Designer when upgrading to v16 as this app is not very maintained at the moment.

[nliechti]

@surajshetty3416 Can someone active please look at this? This fixes something a lot of users will struggle when they uninstall print_designer, as its not that relevant anymore in v16