Proxy Environment Variables are ignored

[codingWombat]

Branch/Environment

• Branch: Master
• Environment: Tyk-pro (on-prem)

Describe the bug
The image of the tib is deployed on an air gapped kubernetes cluster where comunication to services out side the company network are only reachable via a http proxy. After setting the HTTP_PROXY, HTTPS_PROXY and NO_PROXY the identity broker still could not establish a connection.

Reproduction steps
Steps to reproduce the behavior:

1. deploy tib behind a mandatory proxy
2. configure social provider
3. try to authorize via tib
4. Logging contains: dial tcp 79.140.57.13:443: connect: network is unreachable

Actual behavior
The tyk indentiy broker cannot reach upstream services that are behind a proxy

Expected behavior
The tyk identity broker reads and uses the HTTP_PROXY environment variables