sd-event: add sd_event_source_disable_unref() helper
(cherry picked from commit afd15bbb4b6414b9356799c63029e36642dae8e4)
Related: CVE-2020-1712
patch_name: 0315-sd-event-add-sd_event_source_disable_unref-helper.patch
present_in_specfile: true
location_in_specfile: 315
squash_commits: true