move res.send() out of callback, replace with logger.error()

#### What's this PR do?
Our `/retrieve-location` DonorsChoose.org donation MData was timing out, taking longer than 30 seconds to return a response to Mobile Commons. 

Moving the `response.send()` outside of the `requestHttp` callback means that it's sent immediately after the call is made, rather than when the response from the DonorsChoose API returns. 

We also swapped out the error logging in the response for `logger.error` logging. 

#### How should this be manually tested?
I ran through the donations flow with Postman.