LanguageClient: Compile fix

Amends a7fc1631a7.

Change-Id: I868c1ca1bfb5fc0d629e7621597ab71de7aca367
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/languageclient/progressmanager.h

@@ -25,9 +25,11 @@
 
 #pragma once
 
-#include <QFutureInterface>
+#include <coreplugin/progressmanager/futureprogress.h>
+
+#include <QFutureInterface>
+#include <QPointer>
 
-namespace Core { class FutureProgress; }
 namespace LanguageServerProtocol {
 class ProgressParams;
 class ProgressToken;