Issue: Choice field not updating when `_` is used in the ID

When using choice für an own content trype with an underscroe in “title” "title": "mydoc_sidebar" and after changing the frontmatter taxonomy from one choice to another or deleting the field. the underscore title name like in this example "title": "mydoc_sidebar" is not beeing written to the file.

After selecting another title name without an underscore "title": "Choice 2"the title with the underscore can be selected "title": "mydoc_sidebar" again.

This seems only to happen when like in this example there are qoutemarks set. sidebar: '' in the field.

 "frontMatter.taxonomy.contentTypes": [
    {
      "name": "default",
      "pageBundle": false,
      "fields": [
...
    {
      "name": "documentation",
      "pageBundle": false,
      "fields": [
        {
...
        {
          "title": "Sidebar",
          "name": "sidebar",
          "type": "choice",
          "choices": [
            {
              "id": "mydoc_sidebar",
              "title": "mydoc_sidebar"
            },
            {
              "id": "2",
              "title": "Choice 2"
            },
            {
              "id": "3",
              "title": "Choice 3"
            }
          ],
          "multiSelect": true
        },
...

[wemasoe]

@estruyf thank you, it works 😃

[estruyf]

Thanks! This information helped a lot and should be fixed with the upcoming release. Already testable in the beta.