Update aaa_base to rev 473 via SR 827591
    
    https://build.opensuse.org/request/show/827591
    by user oertel + dimstar_suse
    - Update to version 84.87+git20200818.b9dd70f:
      * backup-rpmdb: exit if zypp.pid is there and running
        (bug#1161239)
    
    - Update to version 84.87+git20200818.5220a5f:
      * profile and csh.login: on s390x set TERM to dumb on serial console
      * etc/profile add some missing ;; in case esac statements
      * refresh_initrd call modprobe as /sbin/modprobe (bug#1011548)
      * DIR_COLORS: merge TERM entries with list from (bug#1006973)
      * sort TERM entries in etc/DIR_COLORS
      * DIR_COLORS add TERM rxvt-unicode-256color (bug#1006973)
      * Rename path() to _path() to avoid using a general name.