src/goLanguageServer: change back revealOutputChannelOn to Never

In https://go-review.googlesource.com/c/vscode-go/+/274449, I changed
this property to Error hoping that this reveals the language server
output channel and helps drawing users' attention. It turned out that
causes annoying popup with a cryptic error message

"A request has failed. ..."

Revert this back to Never.

Change-Id: I5292ea945ac177b889ddfd82794593beef8d527a
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/275878
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Peter Weinberger <pjw@google.com>
diff --git a/src/goLanguageServer.ts b/src/goLanguageServer.ts
index 051b23a..965544b 100644
--- a/src/goLanguageServer.ts
+++ b/src/goLanguageServer.ts
@@ -267,7 +267,7 @@
 			},
 			outputChannel: cfg.outputChannel,
 			traceOutputChannel: cfg.traceOutputChannel,
-			revealOutputChannelOn: RevealOutputChannelOn.Error,
+			revealOutputChannelOn: RevealOutputChannelOn.Never,
 			initializationFailedHandler: (error: WebRequest.ResponseError<InitializeError>): boolean => {
 				vscode.window.showErrorMessage(
 					`The language server is not able to serve any features. Initialization failed: ${error}. `