attempts to cold-reboot (factory-reboot) gps module

def cmd_ublox_reset(self, args):
        '''attempts to cold-reboot (factory-reboot) gps module'''
        print("Sending uBlox reset")
        msg = struct.pack("<HBB", 0xFFFF, 0x0, 0)
        self.master.mav.gps_inject_data_send(
            self.target_system,
            self.target_component,
            len(msg),
            bytearray(msg.ljust(110, '\0')))