No real changes, just replace -1 with wxNOT_FOUND in wxBookCtrl code.

Make the code consistently use wxNOT_FOUND instead of -1 everywhere.

See #12622.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65930 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/notebook.h

@@ -96,8 +96,8 @@ public:
     bool SendPageChangingEvent(int nPage);
 
     // sends the event about page change from old to new (or GetSelection() if
-    // new is -1)
-    void SendPageChangedEvent(int nPageOld, int nPageNew = -1);
+    // new is wxNOT_FOUND)
+    void SendPageChangedEvent(int nPageOld, int nPageNew = wxNOT_FOUND);
 
     // wxBookCtrlBase overrides this method to return false but we do need
     // focus because we have tabs