src/config: add toolsEnvVars to the config list to watch

For #1094

Change-Id: Ibe4c405271404ff08200ab6f5d5afcc2a4e162e6
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/300289
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>

Author: hyangah

src/config.ts

@@ -8,7 +8,14 @@ import vscode = require('vscode');
 import { getFromWorkspaceState, updateWorkspaceState } from './stateUtils';
 
 const WORKSPACE_IS_TRUSTED_KEY = 'WORKSPACE_IS_TRUSTED_KEY';
-const SECURITY_SENSITIVE_CONFIG: string[] = ['goroot', 'gopath', 'toolsGopath', 'alternateTools', 'inferGopath'];
+const SECURITY_SENSITIVE_CONFIG: string[] = [
+	'alternateTools',
+	'gopath',
+	'goroot',
+	'inferGopath',
+	'toolsGopath',
+	'toolsEnvVars'
+];
 
 // Initialize the singleton defaultConfig and register related commands.
 // Prompt if workspace configuration was found but had to be ignored until