Fix harmless unused parameter warnings in wxDEBUG_LEVEL==0 build.

These warnings were harmless as they concerned the parameters used inside
wxASSERTs only but there were hundreds if not thousands of them in
wx/strvararg.h alone so all the rest of build output was completely lost in
them.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65046 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/intl.cpp

@@ -238,7 +238,7 @@ bool wxLocale::Init(const wxString& name,
                     const wxString& locale,
                     bool            bLoadDefault
 #if WXWIN_COMPATIBILITY_2_8
-                   ,bool            bConvertEncoding
+                   ,bool            WXUNUSED_UNLESS_DEBUG(bConvertEncoding)
 #endif
                     )
 {