These Chick-fil-A employees weren’t about to let a language barrier get in the way of wishing their coworker a happy birthday. The staff of a Lawton, Oklahoma Chick-fil-A secretly learned how to sing “Happy Birthday” in sign language for their hearing-impaired coworker named James. style=”display:inline-block;width:300px;height:250px” data-ad-client=”ca-pub-8420654331411867″ data-ad-slot=”1313712966″> In order to properly surprise James, the workers waited…