D5888: Get rid of extra margins

[Alexander Volkov]

volkov added a reviewer: Plasma.

REPOSITORY
  R104 KScreen

REVISION DETAIL
  https://phabricator.kde.org/D5888

To: volkov, #plasma
Cc: plasma-devel, ZrenBot, spstarr, progwolff, lesliezhai, ali-mohamed, 
jensreuterberg, abetts, sebas, apol, lukas