Report error message when scope empty

[xieyongbin]

Describe the bug

Report scope is longer than 5 characters when scope empty

Config

rules:
  scope-max-length:
    level: error
    length: 5

Error message

$> echo -n "feat: add new flag" | commitlint
scope is longer than 5 characters

Expected behavior

scope-max-length only check the length of scope and scope-empty check scope empty

Version

# Run the following command
$ commitlint --version
commitlint-rs 0.2.2