A suspect was arrested today in connection with an online threat of gun violence at the University of Chicago that prompted the school to cancel all classes and activities.Joseph Fitzpatrick, a spokesman for the U.S. attorney’s office in Chicago, confirmed the arrest but offered no details, saying only that charges are pending. The University of Illinois at Chicago said that one of its students who lives off-campus was the person arrested, but did not provide details.The university, one of the leading teaching and …