Fix ResourceWarning error due to unclosed socket on exit from roundup_server.

The warning adds clutter that I don't need to parse through.

Author: rouilj

roundup/scripts/roundup_server.py

@@ -1111,6 +1111,7 @@ def run(port=undefined, success_message=None):
         httpd.serve_forever()
     except KeyboardInterrupt:
         print('Keyboard Interrupt: exiting')
+        httpd.socket.close()
 
 
 if __name__ == '__main__':