Ticket 49999 - rpm.mk dist-bz2 should clean cockpit_dist first
    
    Description:  make -f rpm.mk dist-bz2 should always generate this directory
                  from scratch:
    
                      src/cockpit/389-console/cockpit_dist
    
    https://pagure.io/389-ds-base/issue/49999
    
    Reviewed by: spichugi & mreynolds