message: script: Fix copyright_header.py
  This change prevents updating copyright years from "2021" to
  "2021-2017".
diff: @@ -371,7 +371,7 @@ def create_updated_copyright_line(line, last_git_change_year):
  space_split = after_copyright.split(' ')
  year_range = space_split[0]
  start_year, end_year = parse_year_range(year_range)
  - if end_year == last_git_change_year:
  + if end_year >= last_git_change_year:
  return line
  return (before_copyright + copyright_splitter +
  year_range_to_str(start_year, last_git_change_year) + ' ' +
  