after blocking meteor responds with text/plain instead of text/html

[sclausen]

I built my own dos with

for (var i = 0; i < 31416; i++) {
  Meteor.connection._heartbeat._sendPing();
}

I tried it on localhost and Sikka successfully blocks me, but the now always returning "I'am Human" response has the wrong content type text/plain.

[sclausen]

I created the pull request #15 for this issue.