util.jsonschema: Always accept 0 for multipleOf properties Per the JSON schema test suite, 0 is considered "a multiple of anything" and should never be rejected by the multipleOf test. The previous behaviour was to always reject 0. 0 is *not* a valid value for multipleOf itself (which must be >0), but util.jsonschema does not seem to do much/any validation of the provided schema so I haven't added a check for that. I assume there are JSON schema schemas?