Py3 compatibility fix
Py3 compatibility fix

```
>>> import salt.utils.http
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "./salt/utils/http.py", line 43, in <module>
    import salt.config
  File "./salt/config.py", line 300, in <module>
    'pki_dir': os.path.join(salt.syspaths.CONFIG_DIR, 'pki', 'minion'),
  File "/home/vampas/.dotfiles/.ext/pyenv/versions/3.3.6/lib/python3.3/posixpath.py", line 82, in join
    elif not path or path.endswith(sep):
AttributeError: 'member_descriptor' object has no attribute 'endswith'
```

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt