Adopt gravatar plugin

[Michael Kriese]

Hi,
I would like to adopt a plugin:

    Link: https://github.com/jenkinsci/gravatar-plugin
    Pull requests (optional): 
    Status: for adoption
    GitHub Username: viceice
    Jenkins Infrastructure ID:  viceice
    Repository Permission Updater PR: https://github.com/jenkins-infra/repository-permissions-updater/pull/3961

I like to adopt that plugin because the exiting maintainer (an organization?) didn't merged any PR since 2 years. I like to modernize that plugin to follow latest best practises.

Best regards,

Michael Kriese