server: upload "current version" symlinks if requested
server: upload "current version" symlinks if requested

If `fdroid update` generates the "current version" symlinks, then
`fdroid server update` should upload them to the server.

fdroidtravis/fdroidserver,matlink/fdroidserver,fdroidtravis/fdroidserver,f-droid/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,matlink/fdroidserver,matlink/fdroidserver,f-droid/fdroidserver,f-droid/fdroid-server,f-droid/fdroid-server,f-droid/fdroidserver,f-droid/fdroid-server,OneEducation/AppUniverse_Server,f-droid/fdroid-server,OneEducation/AppUniverse_Server,OneEducation/AppUniverse_Server,matlink/fdroidserver,OneEducation/AppUniverse_Server,OneEducation/AppUniverse_Server,f-droid/fdroidserver,matlink/fdroidserver,fdroidtravis/fdroidserver,fdroidtravis/fdroidserver