Issue description

从nacos上发现服务.

• nacos上的服务ip为主机名uaa-service, 一个为ip
• 当负载均衡运行时报 failed to set server peer [uaa-service:20101] err: no host allowed while connecting to upstream
• 造成当负载到为主机名的时候返回网关错误. 负载到ip的时候则正常.

Environment

• apisix version (cmd: apisix version):
• OS (cmd: uname -a):
• OpenResty / Nginx version (cmd: nginx -V or openresty -V):
• etcd version, if have (cmd: run curl http://127.0.0.1:9090/v1/server_info to get the info from server-info API):
• apisix-dashboard version, if have:
• the plugin runner version, if the issue is about a plugin runner (cmd: depended on the kind of runner):
• luarocks version, if the issue is about installation (cmd: luarocks --version):