Support global disablement of partial compilers

[Philogag]

I only need c/c++ and java, and I want disable the others so that no one can use them

[Philogag]

Why I just remove some items in

• vj4/vj4/ui/constant/language.js

is unuseable

[undefined-moe]

If you are using jd4 to judge, you can edit ~/.config/jd4/langs.yaml to remove some languages.
If you are using jd5, you can edit ~/.config/jd5/langs.yaml.

In this case, other languages will be displayed but cannot be judged successfully (an UnsupportedLanguageError will be thrown)

[twd2]

You may need to run npm run build after edit that js file.