Does not use keys from agent or from "identity_files" option

[Andeskjerf]

To use a key, I have to explicitly set it in ~/.ssh/.config using IdentityFile. It would be nice if it got the key from the running SSH agent instead!

I tried using the identity_files option, but it still won't work. Not sure if something is broken with my installation or if it's bugged?

For reference,

./distant connect ssh://user@192.168.1.3 \
        --options 'backend=libssh,identity_files="~/path/to/key",identities_only=true'
Failed to connect to server

Caused by:
    Fatal: unhandled auth case; methods=PUBLIC_KEY, status={PUBLIC_KEY: Denied}

I shared a trace log from another issue I added just now, #251. The command was ran when my agent was running, so if it used the agent it should've gotten the key.