To disgraced former MSNBC host Mehdi Hasan, losing your legs fighting for America is a big joke. Especially if you’re a pro-Israel member of Congress. During a live taping of his show at the anti-Israel ArabCon conference last week, Hasan burst out laughing when his guest, Bassem Youssef, mocked Rep. Brian Mast’s missing legs, which the Florida Republican lost after stepping on an improvised explosive device in Afghanistan in September 2010 during Operation Enduring Freedom. Hasan, a British-