Add jenkins.model.JenkinsLocationConfiguration.xml during installation

[CodeShakingSheep]

Describe the feature request

After a fresh installation I receive a warning

jenkins url is empty but is required for the proper operation of many jenkins features like email notifications, pr status update, and environment variables such as build_url.

Of course this can be configured easily in Jenkins web UI but it would be convenient to have this by default after install. The URL can be set automatically by adding jenkins.model.JenkinsLocationConfiguration.xml in /var/lib/jenkins with the following contents:

<?xml version='1.1' encoding='UTF-8'?>
<jenkins.model.JenkinsLocationConfiguration>
  <adminAddress>[email protected]</adminAddress>
  <jenkinsUrl>https://jenkinsurl.tld</jenkinsUrl>
</jenkins.model.JenkinsLocationConfiguration>

Expected behavior

jenkins.model.JenkinsLocationConfiguration.xml is automatically created during installation with the following variables:

• adminAddress: mail address of yunohost admin user
• jenkinsUrl: configured installation URL

This would also eliminate the mentioned warning after a fresh install.

[yalh76]

Feel free to do a PR for that.

[CodeShakingSheep]

Ok, will create a PR for this in the upcoming weeks when I find the time.