title: socket.gaierror while connecting to remote server
body: <p>I am trying to connect to a remote database as follows:</p>
  
  <pre><code>with SSHTunnelForwarder(
      ssh_address=('10.160.1.24', 22),
      ssh_username='Administrator',
      ssh_password=ssh_password,
      remote_bind_address=('127.0.0.1', 5432)) as server:
      print("test")
  </code></pre>
  
  <p>But I am encountering this error:     </p>
  
  <pre><code>remote_bind_address=('127.0.0.1', 5432)) as server:
    File "/Library/Python/2.7/site-packages/sshtunnel.py", line 879, in __init__
      self._local_interfaces = self._get_local_interfaces()
    File "/Library/Python/2.7/site-packages/sshtunnel.py", line 1378, in _get_local_interfaces
      local_if = socket.gethostbyname_ex(socket.gethostname())[-1]
  socket.gaierror: [Errno 8] nodename nor servname provided, or not known
  </code></pre>