triggerCharacters should not contain `[`

[ZSaberLv0]

Describe the bug
input [ , and auto completion would popup

it's a pain when you want to input something like this:

let xxx = [
        \    xxx,
        \ ]

which would result to this during typing:

let xxx = [something_completed_from_lsp]

To Reproduce
just input [ for vim filetypes