CHICAGO — It was Niklas Hjalmarsson Legacy Night at the United Center on Thursday, but it might as well have been called Stanley Cup reunion night. Hawks stars of the past and present converged as Hjalmarsson was honored in pregame ceremony, Duncan Keith made his first visit to the UC as a member of the Edmonton Oilers and Hawks center Jonathan Toews returned to the ice for the first time since Jan. 26. Tyler Johnson played for the first time in four months after undergoing neck surgery, and defensemen Riley Stillman and Calvin de Haan were back too. Hjalmarsson dropped a ceremonial puck, but…
