remove url-unsafe characters from "current version" symlink names
remove url-unsafe characters from "current version" symlink names

This prevents the URL from having ugly %20 stuff in the app name.

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