Current Behavior

i have two upstream using https protocol, when i configure traffice-splite plugin on one route proxying that two upstream. i find i can not get correct response, it tells me that require "Bad Request This combination of host and port requires TLS"

Expected Behavior

i can use this route with traffice-split plugin proxy https upstream

Error Logs

apisix's response is that
Bad Request
This combination of host and port requires TLS

Steps to Reproduce

1. Run Apisix On Centos7
2. start two applications that uses tls
3. create a route curl "http://127.0.0.1:9080/apisix/admin/routes/1234567890" -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '{"uri":"/health","plugins":{"traffic-split":{"rules":[{"name":"upstream_A","type":"roundrobin","nodes":{"ip:port":10},"timeout":{"connect":15,"send":15,"read":15}}]}},"upstream": {"type": "roundrobin","nodes": {"ip:port": 2}}}'
4. invoke api curl -X GET http://127.0.0.1:9080/health

Environment

• Apisix Version(run apisix version): any version
• Operating system (run uname -a): Linux 3.10.0-957.el7.x86_64 change: added doc of how to load plugin. #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
• OpenResty / Nginx version (run openresty -V or nginx -V): nginx version: openresty/1.19.9.1
• etcd version, if relevant (run curl http://127.0.0.1:9090/v1/server_info): 3.4.0
• APISIX Dashboard version, if relevant:
• Plugin runner version, for issues related to plugin runners:
• LuaRocks version, for installation issues (run luarocks --version):3.4.0