LOS ANGELES, March 5 (Reuters) - Canadian pop singer Carly Rae Jepsen on Tuesday pulled out of a concert for the Boy Scouts of America because of the organization's ban on gay members, becoming the second headliner to pull out of the Scouts' Summer Jamboree show. Jepsen, whose hit single "Call Me Maybe" was nominated for Grammy Song of the Year, said on Twitter that she would not perform for the Boy Scouts because of her support for gay rights.