Remove feature check for variable templates; if we have auto template parameters (C++17) we probably have C++14 as well

include/boost/compat/nontype.hpp

@@ -26,13 +26,9 @@ template<auto V> struct nontype_t: public detail::nontype11<decltype(V), V>
     explicit nontype_t() = default;
 };
 
-# if defined(__cpp_variable_templates) && __cpp_variable_templates >= 201304L
-
 template<auto V>
 BOOST_INLINE_CONSTEXPR nontype_t<V> nontype {};
 
-# endif
-
 #endif
 
 } // namespace compat