Update src/config.jl

Author: ChrisRackauckas

src/config.jl

@@ -279,8 +279,8 @@ This constructor does not store/modify `x`.
 """
 function HessianConfig(f::F,
                        x::AbstractArray{V},
-                       chunk::Chunk,
-                       tag) where {F,V}
+                       chunk::Chunk = Chunk(x),
+                       tag = Tag(f, V)) where {F,V}
     jacobian_config = JacobianConfig(f, x, chunk, tag)
     gradient_config = GradientConfig(f, jacobian_config.duals, chunk, tag)
     return HessianConfig(jacobian_config, gradient_config)