Fix the unable to login problem each time VSCode starts

[houtianze]

First, thanks for this awesome plugin 👍

The change is just one line.

The Problem

• Each time I (re)started VS Code, the extension asks me to login to leetcode.com, though I can see from the directory ~/.lc that the user secrets have been previously saved.

The Cause

• Because the leetcode.cn leetcode-cli plugin is not installed by default with this extension, and if the user has never installed it manually (which most of the time is the case), on line 62 in extension.ts: this call await leetCodeExecutor.switchEndpoint(plugin.getLeetCodeEndpoint()); will throw an exception (because it will eventually try to disable the leetcode.cn plugin, which has not been installed) and the next line which is to load the leetcode user information won't get executed (or error out? I didn't debug further).

The Fix

• Installs leetcode.cn leetcode-cli plugin by default.

[Vigilans]

Thanks for your contribution.

The commit you made has already been covered in a review in another PR: #193 (comment), in which I brought up with a solution but did not get shipped in the latest version.

However, although I know how to suppress the problem, I didn't figure out how the problem([ERROR] Plugin not found!) comes up, and the same problem has been reported by many users in #211.

Your analysis essentially solves my doubt. I then test executing leetcode plugin -d leetcode.cn in a new machine, and the error Plugin not found was popped out as expected.

I can make sure your commit will solve both your problem and one that's discussed above. Good work!

[jdneo]

@houtianze Great work!