refactor: remove cruft

Unable to find a way to trigger the conditionals. See #1404 for reasoning why I took on this test.

lib/recorder.js

@@ -48,21 +48,7 @@ const getBodyFromChunks = function(chunks, headers) {
  // of hex strings so that the responses can be mocked one by one.
  if (common.isContentEncoded(headers)) {
  return {
- // TODO-coverage: Try to add a test for this case. If we can't figure
- // out how to do that, remove the code.
- body: _.map(chunks, function(chunk) {
- if (!Buffer.isBuffer(chunk)) {
- if (typeof chunk === 'string') {
- chunk = Buffer.from(chunk)
- } else {
- throw new Error(
- 'content-encoded responses must all be binary buffers'
- )
- }
- }
-
- return chunk.toString('hex')
- }),
+ body: _.map(chunks, chunk => chunk.toString('hex')),
  }
  }