Help: Fix that bookmarks were not restored

We have to make sure that the help engine is properly set up before
trying to read the bookmark data.

Change-Id: Id57cce5f538472eeac17b39a3640bf2ed77fa56a
Task-number: QTCREATORBUG-14106
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/help/helpplugin.cpp

@@ -30,6 +30,7 @@
 
 #include "helpplugin.h"
 
+#include "bookmarkmanager.h"
 #include "centralwidget.h"
 #include "docsettingspage.h"
 #include "filtersettingspage.h"
@@ -668,6 +669,7 @@ void HelpPlugin::doSetupIfNeeded()
         resetFilter();
         m_setupNeeded = false;
         OpenPagesManager::instance().setupInitialPages();
+        LocalHelpManager::bookmarkManager().setupBookmarkModels();
     }
 }