D5812: Add missing block to make sure initial pid is sent

[Eike Hein]

hein added a dependency: D5747: add pid to plasma window management protocol.

REPOSITORY
  R127 KWayland

REVISION DETAIL
  https://phabricator.kde.org/D5812

To: hein, #plasma, sebas, graesslin
Cc: plasma-devel, #frameworks, ZrenBot, spstarr, progwolff, lesliezhai, 
ali-mohamed, jensreuterberg, abetts, eliasp, sebas, apol, hein, lukas