Simple properties in lists are never validated

[sebdeleze]

Describe the issue
With a list of a simple property, this property is not validated, even with a pattern.

To Reproduce
Check this kind of property:

"simple_not_required": {
    "title": "[issue] Simple element of list are not required.",
    "description": "Simple element must not pass the validation if they are required and empty.",
    "type": "array",
    "minItems": 1,
    "items": {
        "title": "Item",
        "type": "string",
        "pattern": "^.+$",
        "minLength": 1
    }
}