Code review comment for ~hyask/autopkgtest-cloud:skia/package_link

Fixed the commit message, thanks, it's changed.

For the nice to have, there is two problems:
  * it's really hard to verify from a Jinja template that the link is valid: we would have to perform the check from Python and generate the link there, but that feel absolutely overkill for what we want.
  * `auto-package-testing` is not a package, it's a project, so it doesn't make sense to make a link pointing there, where would it be? Sometimes, both links exist [1], but given that we're linking from autopkgtest, the package page makes more sense than the project page, I think.

[1]: see curtin, for example:
project: https://launchpad.net/curtin
package: https://launchpad.net/ubuntu/+source/curtin