Drop forward-secure-sealing code from sd-journal and tools
    
    I asked on fedora-devel@, and the lone reply was from Matthew Miller
    who tried it once when it was introduced and hasn't used it since.
    Dropping this removes the last dependency on libgcrypt and libgpg-error
    in libsystemd, significantly reducing our installation footprint.
    
    Right now libmicrohttpd is still linked to libgcrypt, so
    libsystemd-journal-remote subpackage will pull libgcrypt in.