src/goMain.ts: disable check for active debug session

Rely on VS Code's warning about multiple debug
sessions to prevent users from accidentally starting
multiple debug test sessions.

Fixes golang/vscode-go#1710

Change-Id: I128e4914876bbc6a25a008cc016a4c3c2cd0a8f5
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/349596
Trust: Suzy Mueller <suzmue@golang.org>
Run-TryBot: Suzy Mueller <suzmue@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/src/goMain.ts b/src/goMain.ts
index b6f8d2a..d3b83a0 100644
--- a/src/goMain.ts
+++ b/src/goMain.ts
@@ -352,10 +352,6 @@
 
 	ctx.subscriptions.push(
 		vscode.commands.registerCommand('go.debug.cursor', (args) => {
-			if (vscode.debug.activeDebugSession) {
-				vscode.window.showErrorMessage('Debug session has already been started');
-				return;
-			}
 			const goConfig = getGoConfig();
 			testAtCursor(goConfig, 'debug', args);
 		})