check if _SECURE_SCL is defined not equal to 0

include/fmt/format.h

@@ -324,7 +324,7 @@ inline typename Container::value_type* get_data(Container& c) {
   return c.data();
 }
 
-#ifdef _SECURE_SCL
+#if defined(_SECURE_SCL) && _SECURE_SCL
 // Make a checked iterator to avoid MSVC warnings.
 template <typename T> using checked_ptr = stdext::checked_array_iterator<T*>;
 template <typename T> checked_ptr<T> make_checked(T* p, std::size_t size) {