goLanguageServer: correct default value for formatTool

I forgot to fix it when I changed it from "" to "default".

Change-Id: I241f57447b8ed2c64b6d6274d9576c2fdc52e2bb
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/302029
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/docs/settings.md b/docs/settings.md
index 5f107e3..46a84f9 100644
--- a/docs/settings.md
+++ b/docs/settings.md
@@ -243,7 +243,7 @@
 * `gofumports`: Applies gofumpt formatting and organizes imports.
 
 
-Default: `""`
+Default: `"default"`
 ### `go.generateTestsFlags`
 
 Additional command line flags to pass to `gotests` for generating tests.
diff --git a/package.json b/package.json
index 37fbf6a..fe4c745 100644
--- a/package.json
+++ b/package.json
@@ -1017,7 +1017,7 @@
         },
         "go.formatTool": {
           "type": "string",
-          "default": "",
+          "default": "default",
           "description": "Not applicable when using the language server. Choosing 'goimports', 'goreturns', or 'gofumports' will add missing imports and remove unused imports.",
           "scope": "resource",
           "enum": [