GitLab ignoring no_proxy?

I have GitLab 8.7.4 installed in an environment that needs use of a proxy server to access the internet but not a number of internal servers. I have gitlab.rb configured as

gitlab_rails['env'] = {
  'http_proxy' => "http://webproxy.lon.corp.services:80",
  'https_proxy' => "http://webproxy.lon.corp.services:80",
  'no_proxy' => "localhost,127.0.0.1,.cis.cloud,.ime.company.com,.companyint.com"
}

And it appears that sidekiq and unicorn are picking those up as environment variables.

If I have project with a web hook at http://lyra-dev.cis.cloud:43212/ and test that via the UI, the headers the web hook receives are:

{ 'content-type': 'application/json',
  'x-gitlab-event': 'Push Hook',
  host: 'lyra-dev.cis.trcloud:43212',
  'content-length': '2649',
  via: '1.1 proxy.company.com (squid/3.1.10)',
  'x-forwarded-for': 'unknown',
  'cache-control': 'max-age=259200' }

So for some reason it has gone through a proxy server even though the no_proxy should match the domain.

If I test using curl from the server with appropriate no_proxy environment variable configured that appears to work fine which seems to exclude a transparent proxy getting in the way:

{ 'user-agent': 'curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.19.1 Basic ECC zlib/1.2.3 libidn/1.18 libssh2/1.4.2',
  host: 'lyra-dev.cis.trcloud:43212',
  accept: '*/*' }

I've also tried putting the environment variables into upper cased names (HTTPS_PROXY, NO_PROXY) and having both as I've seen odd behaviour of applications expecting it upper case, but the outcome is the same.

I've also tried with just the one domain in no_proxy but that produced the same headers on the web hook receiver..

Is there anything else I can try to diagnose this?

Thanks.