CMake Authenticated Download From Artifactory

Usage
2

We use FetchContents that use ExternalProject_Add() which has an HTTP_HEADER argument?

That works, but we use no space in set(HTTP_HEADER "X-JFrog-Art-Api:myapikey")!

@ben.boeckel Why has file() a different argument for the same option?

see too Extra HTTP headers for `file(UPLOAD|DOWNLOAD)`