list outputs

def cmd_output_list(self):
        '''list outputs'''
        print("%u outputs" % len(self.mpstate.mav_outputs))
        for i in range(len(self.mpstate.mav_outputs)):
            conn = self.mpstate.mav_outputs[i]
            print("%u: %s" % (i, conn.address))
        if len(self.mpstate.sysid_outputs) > 0:
            print("%u sysid outputs" % len(self.mpstate.sysid_outputs))
            for sysid in self.mpstate.sysid_outputs:
                conn = self.mpstate.sysid_outputs[sysid]
                print("%u: %s" % (sysid, conn.address))