Explain wxSizer::SetVirtualSizeHints() deprecation.

Tell people that FitInside() should be used instead.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66884 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/sizer.h

@@ -843,7 +843,8 @@ public:
         the sizer's minimal size. For windows with managed scrollbars this will set them
         appropriately.
 
-        @deprecated @todo provide deprecation description
+        @deprecated This is exactly the same as FitInside() in wxWidgets 2.9
+        and later, please replace calls to it with FitInside().
 
         @see wxScrolled::SetScrollbars()
     */