JSON schema error message ignored

[isidorn]

Have the following json schema attribute

"externalConsole": {
                    "type": "boolean",
                    "description": "%node.launch.externalConsole.description%",
                    "default": true,
                    "errorMessage": "Hello martin",
                    "enum": []
                }

Notice that the error message is being ignored. It is only repsected in the case that the attribute has a pattern which is not respected.

Need this for #11209