data[keys1.0] when using object format of `additionalProperties`

[jeffijoe]

Given schema:

{
  type: 'object',
  additionalProperties: {
    type: 'string'
  }
}

Validating:

{ hello: 123 }

Results in the following:

[ { field: 'data[keys1.0]',
    message: 'is the wrong type',
    value: 123,
    type: 'string' } ]

Expected output:

[ { field: 'data.hello',
    message: 'is the wrong type',
    value: 123,
    type: 'string' } ]