src/goLanguageServer.ts: restart if go.toolsEnvVars changes

go.toolsEnvVars setting affects how gopls launches.
See src/goEnv.ts toolExecutionEnvironment.

Updates #628

Change-Id: I6294af2d4dd1822b7dfbe571532c6f2d18089608
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/254370
Reviewed-by: Rebecca Stambler <rstambler@golang.org>

src/goLanguageServer.ts

@@ -492,7 +492,9 @@ export function watchLanguageServerConfiguration(e: vscode.ConfigurationChangeEv
 		e.affectsConfiguration('go.useLanguageServer') ||
 		e.affectsConfiguration('go.languageServerFlags') ||
 		e.affectsConfiguration('go.languageServerExperimentalFeatures') ||
-		e.affectsConfiguration('go.alternateTools')
+		e.affectsConfiguration('go.alternateTools') ||
+		e.affectsConfiguration('go.toolsEnvVars')
+		// TODO: Should we check http.proxy too? That affects toolExecutionEnvironment too.
 	) {
 		restartLanguageServer();
 	}