jnunemaker/httparty — pull request #156 by brookemckim (2012-08-10 14:42:39+00:00)
Title: Digest Auth: Opaque value incorrectly sent in request when not present in response from server.

When attempting to use Digest auth against Apache/2.2.22 (Ubuntu) I was getting the following error:

```
[Fri Aug 10 08:49:47 2012] [error] [client 192.168.50.86] Digest: received invalid opaque - got `'
```

This happens because Apache is not responding with an opaque value in the header. When HTTParty responds it sends an empty value for opaque. This fix omits sending the opaque value when the server does not require it.