Dont send body if empty

[alh3im]

For some custom install of couchdb app, if body is empty, connection may be reset by peer.

Example with the npm registry couchapp.

[alh3im]

I've added a new commit with cancel the first one.

[isaacs]

Can you please add some tests for this?

[alh3im]

Do you mean unit tests or manual functional tests ?

[isaacs]

I mean unit tests, like the ones in /test/*.js. You can probably piggie-back on an existing test, just make a request like the one where you found this. Make sure the test fails without the patch, and passes with the patch.