- Update to 2.2.1
https://www.keepalived.org/release-notes/Release-2.2.1.html
https://www.keepalived.org/release-notes/Release-2.2.0.html
https://www.keepalived.org/release-notes/Release-2.1.5.html
https://www.keepalived.org/release-notes/Release-2.1.4.html
https://www.keepalived.org/release-notes/Release-2.1.3.html
https://www.keepalived.org/release-notes/Release-2.1.2.html
https://www.keepalived.org/release-notes/Release-2.1.1.html
https://www.keepalived.org/release-notes/Release-2.1.0.html
- enable systemd integration via libsystemd (new BR: libsystemd)
- switch to systemd_ordering instead of systemd_requires
- sync configure options with the configure script