Issue #50683 - Makefile.am contains unused RPM-related targets
    
    Bug Description:
    Makefile.am contains some targets very similar to the ones in rpm.mk but
    most likely unused by anyone and also untouched recently unlike the
    rpm.mk ones.
    
    Fix Description:
    Remove the targets for cleanness and reducing confusion.
    
    Fixes https://pagure.io/389-ds-base/issue/50683
    
    Author: Matus Honek <mhonek@redhat.com>
    
    Review by: firstyear, mreynolds (thanks!)