additionalProperties should be by default allowed

Prerequisites

• I have read the documentation;
• In the case of a bug report, I understand that providing a SSCCE example is tremendously useful to the maintainers.
• Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

Description

Json schema by default allows additional properties in objects (json-schema-doc, there is this paragraph "The additionalProperties keyword is used to control the handling of extra stuff, that is, properties whose names are not listed in the properties keyword. By default any additional properties are allowed."). In form, its unfortunately treated as false when not specified.

Playground

Steps to Reproduce

1. Create schema with "type":"object" , without specified "additionalProperties".

Expected behavior

I should be able to add aditional properties to object.

Actual behavior

Its not possible to add additional properties

Version

2.4.0