defining stream vector variables more than one pair is not working

Defining both wind and stress components in namelist_definition_datm.xml is not working. I have tested both

```
u:v,taux:tauy
```

and

```
'u:v','taux:tauy'
```

syntaxes and the stress components do not appear in the **datm.streams.xml** file and shown as `u:v`