Update folks to version 0.15.3 / rev 54 via SR 929704
    
    https://build.opensuse.org/request/show/929704
    by user dimstar + dimstar_suse
    - Require libfolks-telepathy%{soversion} from the -devel package:
      we install the .so symlink and must thus guarantee to have the
      link target preset too. (forwarded request 929645 from dimstar)