Fix client settings cannot be overridden

[vljosa-vivodyne]

Create hash table with :test 'equal so that
lsp-register-custom-settings can be called again to override settings.

Resolves #4382

[yyoncho]

Thank you!

[alanz]

FYI, this change causes my semantic tokens to disappear in rust-mode, set up as

(use-package lsp-mode
  :hook (scala-mode rust-mode rust-ts-mode)
  ...
  :custom
  (lsp-semantic-tokens-enable t)
...

If I comment it out, they come back.

[vljosa-vivodyne]

@alanz, I'm not able to reproduce. I'm not sure I fully understand how semantic tokens are supposed to work, but I think the pink distance_to in let distance = point_a.distance_to(&point_b); means it's working. (At least that's something that changes with (lsp-semantic-tokens-enable t).)

If I'm wrong, can you please give a piece of example code and explain how to see whether semantic tokens are working so I can try again to reproduce?

[alanz]

For rust analyzer, references will show up bold, and mutable items underlined. So making a small change to RA code, I get

ra_fixture is both bold and underlined. If you remove the mut (as it normally is), the underline disappears.

[alanz]

We chose bold and underline to keep things simple for themes

[alanz]

And after the update today it works. And I don't see anything in the commit history that could have done it. It must have been some other part that updated. Sorry for the noise.