tdf#96896-Fix infinite recursion to prevent Writer crash

To prevent infinite recursion set m_xOwner to null.
Removed impl_sendTitleChangedEvent from disposing method ensuring that
title is never constructed for a component that is disposing.

Change-Id: I9bc20a9a582d5d911509d2aa30fb0d0122eb588e
Reviewed-on: https://gerrit.libreoffice.org/23509Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

framework/source/fwe/helper/titlehelper.cxx

@@ -249,13 +249,13 @@ void SAL_CALL TitleHelper::disposing(const css::lang::EventObject& aEvent)
     // SYNCHRONIZED ->
     aLock.reset ();
 
+         m_xOwner        = nullptr;
          m_sTitle        = OUString ();
          m_nLeasedNumber = css::frame::UntitledNumbersConst::INVALID_NUMBER;
 
     aLock.clear ();
     // <- SYNCHRONIZED
 
-    impl_sendTitleChangedEvent ();
 }
 
 void TitleHelper::impl_sendTitleChangedEvent ()