Investigate cause for nginx invalid chunked response error

[ansell]

There was an nginx error that occurred while downloading large files (same test case as #208 , so not sure if this is unique to this situation). The error refers to "invalid chunked response", with the following error message. Not sure what to do, but logging this issue to keep track of it for future when we have a chance to research it:

2018/11/13 09:13:36 [error] 9971#9971: *24547 upstream sent invalid chunked response while reading upstream, client: REDACTED, server: doi.ala.org.au, request: "GET /doi/0d01a947-265c-4450-88e8-1aeebccd45c3/download;jsessionid=REDACTED HTTP/2.0", upstream: "http://127.0.0.1:8080/doi/0d01a947-265c-4450-88e8-1aeebccd45c3/download;jsessionid=REDACTED", host: "doi.ala.org.au"