HttpClient uses synchronous network calls in both of its implementations, and does not have a cancellation mechanism. This means that when an OpCtx running an HttpClient is cancelled, it can take up to HttpClient::_timeout seconds to actually cancel. We should look through all the cases we use HttpClient and make sure that we are okay with waiting this long (this likely requires input from Repl, since I believe they own killOperation() and would know the timing requirements on it). Specifically, we should look at the cases where we don't set a specific timeout and so we default to 60 seconds.