Fix token-receiver url generation logic

[pkukielka]

Changes

VSC uses two types of login redirect, either by vscode://sourcegraph.cody-ai uri if browser and os supports that, or through local http server if it does not.

Url we use to trigger redirect looks like that:

https://sourcegraph.com/users/pkukielka-zvxqk/settings/tokens/new/callback?requestFrom=CODY&tokenReceiverUrl=http%3A%2F%2F127.0.0.1%3A58543%aaaabbbbccccddddeeeeffffgggghhhhhh.auth/openidconnect/login?prompt_auth=github&pc=sams&redirect=/user/settings/tokens/new/callback?requestFrom=CODY&tokenReceiverUrl=http%3A%2F%2F127.0.0.1%3A58543%aaaabbbbccccddddeeeeffffgggghhhhhh

But should be:

https://sourcegraph.com/.auth/openidconnect/login?prompt_auth=github&pc=sams&redirect=%2Fuser%2Fsettings%2Ftokens%2Fnew%2Fcallback%3FrequestFrom%3DCODY%26tokenReceiverUrl%3Dhttp%3A%2F%2F127.0.0.1%3A63992%aaaabbbbccccddddeeeeffffgggghhhhhh

It was broken long time ago but we never noticed: #4664

Test plan

1. Sing out from current account
2. Close VSC
3. Reopen VSC and sing in using GitHutb
4. When Authorize Cody - VS Code Extension? window will show make sure it opens in newest Chrome (if that is not the case you can simply copy-paste it to Chrome window)
5. Click Authorize
6. Make sure you are properly signed in

[bobheadxi]

workaround LGTM for now, thanks!