Optionnal scope is optionnal, but parenthisis of that scope are not

[dlarr]

Hello, first of all thanks for this wonderfull library, I use it a lot.

Now the question

I noticed that if I omit scope in my commit, the changelog generation won't include that commit.

Examples:

This commit will appear in changelog after standard-version cli command
feat(some scope): some message commit

This one will also appear
feat(): some message commit

But this one will not appear, which is strange because it does respect conventional commit
feat: some message commit

Am I alone in this case ? Here is my versionrc (i obfuscated non relevant infos)
Also URL format must be used that way on bitbucket instances

{
    "header": "My awsome lib CHANGELOG",
    "types": [
        {"type": "revert", "section":"Reverts", "hidden":false},
        {"type": "feat", "section":"Features", "hidden":false},
        {"type": "fix", "section":"Bug fixes", "hidden":false},
        {"type": "improvement", "section":"Feature improvements", "hidden":false},
        {"type": "docs", "section":"Docs", "hidden":false},
        {"type": "refactor", "section":"Code refactoring", "hidden":false},
        {"type": "perf", "section":"Performance improvements", "hidden":false},
        {"type": "chore", "section":"Changes to auxiliary tools", "hidden":false}
    ],
    "compareUrlFormat":  "https://some.bitbucket.com/projects/PROJECT/repos/myrepo/compare/diff?targetBranch=refs%2Ftags%2F{{previousTag}}&sourceBranch=refs%2Ftags%2F{{currentTag}}",
    "issueUrlFormat": "https://some.jira.com/browse/{{id}}",
    "commitUrlFormat": ""https://some.bitbucket.com/projects/PROJECT/repos/myrepo/commits/{{hash}}",
    "skip": {
        "commit": false,
        "tag": false
    }
}

thank you for any answers :)