cleanup code

Author: shun

denops/ddc-sources/ddc-vim-lsp.ts

@@ -9,10 +9,6 @@ import {
   vars,
 } from "https://deno.land/x/ddc_vim@v0.5.0/deps.ts#^";
 
-import {
-  once
-} from "https://deno.land/x/denops_std@v1.8.1/anonymous/mod.ts";
-
 export class Source extends BaseSource {
   async onInit(args: {
     denops: Denops,