alloc/allocator: add forgotten type parameter for forward call

alloc/allocator.hpp

@@ -28,9 +28,10 @@ namespace util::alloc {
     public:
         typedef ValueT value_type;
 
+
         template <typename ...Args>
         explicit allocator (Args&& ...args):
-            m_backing (std::forward (args)...)
+            m_backing (std::forward<Args> (args)...)
         { ; }