fix: correctly serialize a Space class to the json format in the JSONExpression

src/jsonexpression.cpp

@@ -155,10 +155,9 @@ void JSONExpression::esc(const pt::Space & space, pt::Stream & stream, const FT
 	else
 	{
 		// when serializing as json put it directly without escaping
-
 		pt::TextStream tmp_stream;
 		space.serialize_to_json_stream(tmp_stream, pretty_print);
-		BaseExpression::esc(tmp_stream, stream, field_type, model_env);
+		stream << tmp_stream;
 	}
 }