tdf#122056: Catch DisposedExceptions everywhere

Change-Id: I6bdb9aa89a8a5181b096f47f90ab6fb5711e7447
Reviewed-on: https://gerrit.libreoffice.org/69541
Tested-by: Jenkins
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

vcl/inc/qt5/Qt5AccessibleWidget.hxx

@@ -136,6 +136,7 @@ public:
 
 private:
     css::uno::Reference<css::accessibility::XAccessible> m_xAccessible;
+    css::uno::Reference<css::accessibility::XAccessibleContext> getAccessibleContextImpl() const;
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */