add support for env variable `no_proxy`
openconnect is taking the proxy from the env variable https_proxy
but does not consider no_proxy
as well. The latter usually contains a list of domains that can be reached without a proxy even if one is configured.
Here is a repro for OpenConnect version v8.10
export http_proxy=http://172.17.0.1:8118
export no_proxy=localhost,127.0.0.1,::1,.company.com
openconnect --juniper https://host.company.com/vpn
...
Connected to 172.17.0.1:8118
Requesting HTTP proxy connection to host.company.com:443
SSL negotiation with host.company.com
...
Running the same with --libproxy
does not go via the proxy as expected, but the builtin proxy support lacks deny-list support i would say.