Please sort names according to configuration

[DS-BSZ]

Hello,

thanks for this great plugin.

One issue I have found: When I want to change an author, the list of name is always sorted by firstname, even when 'users display format' is set to 'lastname, firstname' in Redmine settings.

Could you set the display order within the plugin like it is in Redmine itself, i.e. alphabetical depending on the display format of the whole name?

Best regards,
Dan