Dear BILL MAHER: It’s your right, as an American male over 15 years old, to not know who ZAYN MALIK is. But as host of a TV show with 4 million viewers, it is your job to figure out that a man whose first and last names are both Arabic just might possibly be Muslim, especially before making a cheap joke suggesting he looks like another young Muslim male who happens to be a terrorist. “Neither I not anyone on our staff knew [he was Muslim]; how could we?” you said with a poop-eating grin on FRIDAY’s show, defending yourself against accusations that your joke about ZAYN MALIK and DZHOKHAR TSARNAEV on your previous show was Islamophobic. This is why diversity matters in hiring. If the staff of your HBO show doesn’t include a single person who knows, or can figure out, that a singer who was a central figure in one of the most popular groups in the world is Muslim, you shouldn’t be laughing about it. You should be apologizing…