Backport of sabre-io/vobject#716 -- support RDATE together with RRULE.#2088

rotdrop wants to merge 2 commits intonextcloud:masternextcloud/3rdparty:masterfrom

rotdrop:bugfix/sabre-supprot-rrules-with-rdatesrotdrop/nextcloud-3rdparty:bugfix/sabre-supprot-rrules-with-rdatesCopy head branch name to clipboard