D4759: [kcheckpass] Drop command line option for username

[Aleix Pol Gonzalez]

apol accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R133 KScreenLocker

BRANCH
  no-username-option

REVISION DETAIL
  https://phabricator.kde.org/D4759

To: graesslin, #plasma, apol
Cc: plasma-devel, progwolff, lesliezhai, ali-mohamed, jensreuterberg, abetts, 
sebas, apol