fixed gauge overflow

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@17533 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/progdlgg.cpp

@@ -322,7 +322,7 @@ wxProgressDialog::Update(int value, const wxString& newmsg)
 
     wxASSERT_MSG( value <= m_maximum, wxT("invalid progress value") );
 
-    if ( m_gauge )
+    if ( m_gauge && value < m_maximum )
     {
         m_gauge->SetValue(value + 1);
     }