Core: Remove parent pointer from IOptionPage constructor

Not used anymore.

Change-Id: Ic44ce021b1f952337a3193454b5b6649d5847446
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/coreplugin/dialogs/ioptionspage.cpp

@@ -240,8 +240,7 @@ static QList<IOptionsPage *> g_optionsPages;
     Constructs an options page with the given \a parent and registers it
     at the global options page pool if \a registerGlobally is \c true.
 */
-IOptionsPage::IOptionsPage(QObject *parent, bool registerGlobally)
-    : QObject(parent)
+IOptionsPage::IOptionsPage(bool registerGlobally)
 {
     if (registerGlobally)
         g_optionsPages.append(this);