v4.81

This release adds the following new features:

• Global Search: Use translated color names.
  Thanks to jrsupplee and xet7.

and fixes the following bugs:

• Restore original working Dockerfile.
  Thanks to gpalyu and xet7.
• Reverted Cards, custom fields are displayed in alphabetic order from Wekan v4.71
  https://github.com/wekan/wekan/pulls/3417 because it caused board not
  loading.
  Thanks to olivierlambert and xet7.

Thanks to above GitHub users for their contributions and translators for their translations.