Unable to manually synchronize a site if it has no jobs to start with

Currently the Manage Jobs button is only displayed on a Site page when a site has jobs already synchronized, and this dialog that is opened through that button is the only place that contains the Sync Site action.

This blocks admins from refreshing the job list of a site when they first add a site and later add jobs to that site.

As a workaround, an admin can edit the site and save it without making changes, as this will also trigger the synchronization of the jobs.

Alternatively, if the "Auto enable new jobs" option is checked for the site, the admins can add new jobs to the Jenkins site and trigger build of them, this will also result in the jobs being synchronized, but this is limited to the actual job that the build is of.