add missing GetVeto method

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75622 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/event.h

@@ -4083,6 +4083,11 @@ public:
         You can only veto a shutdown if CanVeto() returns @true.
     */
     void Veto(bool veto = true);
+
+    /**
+       Returns whether the Veto flag was set.
+    */
+    bool GetVeto() const;
 };