Removed prefixing of doubles between -1 and 1 with 0.

This resulted in values like `00.018` in the AST's NumConstNode which
cannot be read by some JSON readers (e.g. Mathworks' jsondecode).

src/ExprNode.cc

@@ -451,8 +451,6 @@ void
 NumConstNode::writeJsonAST(ostream &output) const
 {
   output << R"({"node_type" : "NumConstNode", "value" : )";
-  if (double testval = datatree.num_constants.getDouble(id); testval < 1.0 && testval > -1.0 && testval != 0.0)
-    output << "0";
   output << datatree.num_constants.get(id) << "}";
 }