[tests] fix dig output TXT parsing (#6577)
[tests] fix dig output TXT parsing (#6577)


abtink/openthread,abtink/openthread,jwhui/openthread,srickardti/openthread,srickardti/openthread,openthread/openthread,openthread/openthread,jwhui/openthread,openthread/openthread,srickardti/openthread,srickardti/openthread,abtink/openthread,jwhui/openthread,openthread/openthread,abtink/openthread,jwhui/openthread