Better checking to avoid object creation

lib/jsonpath.js

@@ -55,7 +55,7 @@ function JSONPath (opts, obj, expr) {
 
     if (opts.autostart !== false) {
         var ret = this.evaluate((objArgs ? opts.json : obj), (objArgs ? opts.path : expr));
-        if (!ret) {
+        if (!ret || typeof reg !== 'object') {
             throw {avoidNew: true, value: ret, message: "JSONPath should not be called with 'new'"};
         }
     }