Ticket 49601 - Replace HAVE_SYSTEMD define with WITH_SYSTEMD in svrcore
Bug Description: As former configure of svrcore is not used after the
merge of svrcore, and the svrcore's --with-systemd configure flag
handling seems to not have been merged to the 389-ds-core configure,
and configuring svrcore --with-systemd defines HAVE_SYSTEMD which is
different from define WITH_SYSTEMD used in 389-ds-base, the systemd
support in svrcore is not effectively turned on when compiling
389-ds-base with --with-systemd.
Fix Description: Use the very same define as 389-ds-base
uses (WITH_SYSTEMD) instead of the former one of svrcore, which is
obviously inheritted into the svrcore code as well, thus effectively
selecting a code to be compiled based on the --with-systemd configure
flag.
https://pagure.io/389-ds-base/issue/49601
Author: mhonek
Review by: mreynolds, spichugi