src/goLanguageServer: remove go-langserver deprecation warning

It was deprecated a year ago. It's time to finish clean up.

Change-Id: Ie58969d7abb9bc2070c69d8d4038d2e6cc289290
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/295709
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: Rebecca Stambler <rstambler@golang.org>
diff --git a/src/goInstallTools.ts b/src/goInstallTools.ts
index 61a2ea4..b53cb08 100644
--- a/src/goInstallTools.ts
+++ b/src/goInstallTools.ts
@@ -16,7 +16,6 @@
 import { getGoConfig } from './config';
 import { toolExecutionEnvironment, toolInstallationEnvironment } from './goEnv';
 import { addGoRuntimeBaseToPATH, clearGoRuntimeBaseFromPATH } from './goEnvironmentStatus';
-import { getLanguageServerToolPath } from './goLanguageServer';
 import { logVerbose } from './goLogging';
 import { restartLanguageServer } from './goMain';
 import { addGoStatus, initGoStatusBar, outputChannel, removeGoStatus } from './goStatus';
@@ -40,7 +39,7 @@
 	GoVersion,
 	rmdirRecursive
 } from './util';
-import { correctBinname, envPath, getCurrentGoRoot, getToolFromToolPath, setCurrentGoRoot } from './utils/pathUtils';
+import { correctBinname, envPath, getCurrentGoRoot, setCurrentGoRoot } from './utils/pathUtils';
 import util = require('util');
 import vscode = require('vscode');
 
@@ -539,25 +538,6 @@
 	if (!goConfig['useLanguageServer']) {
 		return;
 	}
-
-	const usingSourceGraph = getToolFromToolPath(getLanguageServerToolPath()) === 'go-langserver';
-	if (usingSourceGraph && goVersion.gt('1.10')) {
-		const promptMsg =
-			'The language server from Sourcegraph is no longer under active development and it does not support Go modules as well. Please install and use the language server from Google or disable the use of language servers altogether.';
-		const disableLabel = 'Disable language server';
-		const installLabel = 'Install';
-		const selected = await vscode.window.showInformationMessage(promptMsg, installLabel, disableLabel);
-		if (selected === installLabel) {
-			await installTools([getTool('gopls')], goVersion);
-		} else if (selected === disableLabel) {
-			const inspectLanguageServerSetting = goConfig.inspect('useLanguageServer');
-			if (inspectLanguageServerSetting.globalValue === true) {
-				goConfig.update('useLanguageServer', false, vscode.ConfigurationTarget.Global);
-			} else if (inspectLanguageServerSetting.workspaceFolderValue === true) {
-				goConfig.update('useLanguageServer', false, vscode.ConfigurationTarget.WorkspaceFolder);
-			}
-		}
-	}
 }
 
 function getMissingTools(goVersion: GoVersion): Promise<Tool[]> {
diff --git a/src/goLanguageServer.ts b/src/goLanguageServer.ts
index 49c3438..b534127 100644
--- a/src/goLanguageServer.ts
+++ b/src/goLanguageServer.ts
@@ -943,13 +943,6 @@
 			);
 			return;
 		}
-		// Check if the user has the deprecated "go-langserver" setting.
-		// Suggest deleting it if the alternate tool is gopls.
-		if (alternateTools['go-langserver']) {
-			vscode.window.showErrorMessage(`Support for "go-langserver" has been deprecated.
-The recommended language server is gopls. Delete the alternate tool setting for "go-langserver" to use gopls, or change "go-langserver" to "gopls" in your settings.json and reload the VS Code window.`);
-			return;
-		}
 	}
 
 	// Prompt the user to install gopls.