fix(httputil): change order of struct fields

This is because the marshals traverse structs in field order, and
it makes more sense for the fields to have status first and details
second.

pkg/httputil/httperrors.go

@@ -38,8 +38,8 @@ const (
 // For example, and error can be serialized to JSON or YAML. Likewise, the
 // string marshal can convert it to a string.
 type Error struct {
-	Msg    string `json:"message, omitempty"`
 	Status string `json:"status"`
+	Msg    string `json:"message, omitempty"`
 }
 
 // Error implements the error interface.