Comment on February 2017 CU for SharePoint Server 2016 is available for download by Stefan Goßner

Hi Piotr,
NAPA is Office 365 development tools in SPO. It can be optionally installed from the Store in an SPO Developer site.
The option to install it was also available in SharePoint 2016 as SharePoint 2016 was derived from SPO but it does not work on SP2016.
This fix removes the option to install NAPA as it caused confusion for some users.
More details about NAPA:
https://msdn.microsoft.com/en-us/library/office/jj220041.aspx
Cheers,
Stefan