Ticket 48318 - Do not delete a changelog while disabling a replication by suffix
    
    Bug Description: If we have a few replicated suffixes on the single
                     instance, they will use the one changelog
                     ("cn=changelog5,%s" % DN_CONFIG).
    
                     If we disable the replication on the one of them by:
                     instance.replica.disableReplication(suffix=SUFFIX_2)
    
                     Then, according to the current logic, the changelog
                     will be deleted. But it is still required by another
                     replicated suffixes.
    
    Fix Description: Remove the 'Delete the changelog' block from
                     disableReplication method of replica.py module.
    
    https://fedorahosted.org/389/ticket/48318
    
    Review by: mreynolds (Thanks!)