By Padraic Halpin DUBLIN (Reuters) – Ireland clinched their first Triple Crown in four years on Saturday with a 26-5 victory over Scotland that kept the Six Nations championship alive for a few hours, until France completed the Grand Slam against England in Paris. While Ireland were not at their very best, a first clean sweep of their “home nation” rivals in four years looked rarely in doubt after first half tries from front rows Dan Sheehan and Cian Healy and a third on the hour from Josh van der Flier. Replacement scrumhalf Conor Murray’s last-gasp bonus point try meant France had to win in …