itip-formatter: Use whole URL value as a link href
The attached email beat_the_heat.mbox has a Content-Type: text/calendar; charset=UTF-8; method=PUBLISH; component=VEVENT
MIME part, containing URL:https://my.aegee.eu/summeruniversity/su-beat-the-heat-
. The final hyphen of the URL is essential. Evolution does not include the final hyphen in the generated hyperlink in the iTIP formatter.