manifest.xml does not allow for https in homepage URL

Running 64-bit Renoise 3.1.0 on Windows 10 Pro.

Created a tool.

Edited manifest,xml to set the home page using a URL with the https protocol:

Bundled up the tool and installed it.

Got an error message

Expected an empty string or an http based URL as HomePage in the global manifest.xml

If I change the https protocol to http this error goes away.