removed unnecessary join from query in isLinkableCourse() method.
removed unnecessary join from query in isLinkableCourse() method.

justinchu17/ilios,dartajax/ilios,justinchu17/ilios,ilios/ilios,thecoolestguy/ilios,ilios/ilios,stopfstedt/ilios,Trott/ilios,Trott/ilios,thecoolestguy/ilios,stopfstedt/ilios,justinchu17/ilios,dartajax/ilios,justinchu17/ilios