Access API Server 502 after using HTTPS proxy

[wisheen]

General remarks

This form is to report bugs. For general usage questions refer to our Slack channel KubeSphere-users

Describe the bug Using Nginx as a reverse proxy, when configured for HTTPS access, All /api/xx requests report 502 errors， But /kapis/xxx are fine。Using ip:30880 is also correct。

For UI issues please also add a screenshot that shows the issue.

Versions used(KubeSphere/Kubernetes) KubeSphere: 2.1.0 Kubernetes: (If KubeSphere installer used, you can skip this)

Environment How many nodes and their hardware configuration: 3 masters: 2cpu/4g 3 nodes: 4cpu/16g

(and other info are welcomed to help us debugging)

To Reproduce Steps to reproduce the behavior:

Expected behavior A clear and concise description of what you expected to happen. The console supports HTTPS proxy access