fix(init.sls): fix `salt-lint` errors

```bash
Examining users/init.sls of type state
[206] Jinja variables should have spaces before and after: {{ var_name }}
users/init.sls:176
    - expire: {{ (user['expire'] / 86400) | int}}

[206] Jinja variables should have spaces before and after: {{ var_name }}
users/init.sls:202
      - {{optional_group}}
```