catch exception like text_wrapper_get_caret_offset does

Change-Id: I7d681a5cd58af60005eefa9969ec975d5cfc5580
diff --git a/vcl/unx/gtk/a11y/atkutil.cxx b/vcl/unx/gtk/a11y/atkutil.cxx
index 984f053..5ac47e3 100644
--- a/vcl/unx/gtk/a11y/atkutil.cxx
+++ b/vcl/unx/gtk/a11y/atkutil.cxx
@@ -92,7 +92,14 @@ atk_wrapper_focus_idle_handler (gpointer data)
                    wrapper_obj->mpText.set(wrapper_obj->mpContext, css::uno::UNO_QUERY);
                    if ( wrapper_obj->mpText.is() )
                    {
                        gint caretPos = wrapper_obj->mpText->getCaretPosition();
                        gint caretPos = -1;

                        try {
                            caretPos = wrapper_obj->mpText->getCaretPosition();
                        }
                        catch(const uno::Exception&) {
                            g_warning( "Exception in getCaretPosition()" );
                        }

                        if ( caretPos != -1 )
                        {