Don't pass locale_ref into arg_formatter constructor in printf_arg_fo…

…rmatter

include/fmt/printf.h

@@ -235,7 +235,7 @@ class printf_arg_formatter : public arg_formatter<Char> {
 
  public:
   printf_arg_formatter(OutputIt iter, format_specs<Char>& s, context_type& ctx)
-      : base{iter, s, locale_ref()}, context_(ctx) {}
+      : base{iter, s}, context_(ctx) {}
 
   OutputIt operator()(monostate value) { return base::operator()(value); }