Update acl to version 2.3.1 / rev 50 via SR 893445
    
    https://build.opensuse.org/request/show/893445
    by user dirkmueller + dimstar_suse
    - modernize spec-file (move license to licensedir)
    
    - Update to version 2.3.1
      * Update German translation
      * getfacl: fix indent in --help output
      * getfacl: Add --one-file-system option, with this option getfacl
        will not cross mount points
      * Fix segfault on allocation failure
      * Avoid SIGSEGV with link-time optimisation enabled
    - Use SourceUrls