d145091 Remove compatible code with EL5 in bash completion

Authored and Committed by cqi 5 years ago
    Remove compatible code with EL5 in bash completion
    
    There is no EL5 release for rpkg any more. _get_comp_words_by_ref is
    workable in all Fedora releases and EPEL.
    
    Signed-off-by: Chenxiong Qi <cqi@redhat.com>