allow compilation with wxUSE_DATETIME == 0 (patch 679822)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@19128 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/gridctrl.cpp

@@ -33,6 +33,8 @@
 // wxGridCellDateTimeRenderer
 // ----------------------------------------------------------------------------
 
+#if wxUSE_DATETIME
+
 // Enables a grid cell to display a formated date and or time
 
 wxGridCellDateTimeRenderer::wxGridCellDateTimeRenderer(wxString outformat, wxString informat)
@@ -121,6 +123,8 @@ void wxGridCellDateTimeRenderer::SetParameters(const wxString& params){
         m_oformat=params;
 }
 
+#endif // wxUSE_DATETIME
+
 // ----------------------------------------------------------------------------
 // wxGridCellChoiceNumberRenderer
 // ----------------------------------------------------------------------------