Custom lsp server config replace whole default configuration.

[JoeMob]

Here's my config of pylsp to enable isort of pylsp
lua/user/lsp-servers/pylsp.lua:
return { settings = { pylsp = { plugins = { pyls_isort = { enabled = true }, }, }, }, }.
Due to the Steps to modify plugin configs part of the wiki, I think the table returned should just update the pyls_isort property but not replace the whole config.

[ayamir]

#1376