The 389-ds-base RPM is not installed by default on a Red Hat Enterprise Linux 7 system. It is needed only by the 389-ds server, not by the clients which use LDAP for authentication. If the system is not intended for use as an LDAP Server it should be removed.
Unnecessary packages should not be installed to decrease the attack surface of the system. While this software is clearly essential on an LDAP server, it is not necessary on typical desktop or workstation systems.