Jeremy Soles will run the Marine Corps Marathon this Sunday in a gas mask. Why? Because it’s hard, but not as hard as the life of a wounded Marine. “The mask is an icon,” said Soles, who got out of the Corps in 2004 and has run several races wearing a gas mask as part of Team X-T.R.EM.E., which is raising money for the Wounded Warrior Project. “The time I spend in a mask is short, difficult and requires mental and physical fortitude,” he said, pointing out that doing it is not unlike what so many wounded guys go through,…