A federal judge declined to sanction a school district for allowing a nurse to delete a photograph later sought in litigation of a student’s bruised hip she had taken with her cellphone.In a written opinion, U.S. Magistrate Judge Susan E. Cox of the Northern District of Illinois rejected the argument that Oswego Community Unit School District 308 violated its duty under the Federal Rules of Civil Procedure to preserve electronically stored information.The photograph was sought by Bradley and Elizabeth Hamilton, who …