Error message of missing qml2puppet shows up twice when shown for the first time

Steps to reproduce:

• start Creator with clean settings
• make sure you have a Kit for Qt5
• create a new Qt Quick 2 UI
• switch to Designer view

Current behavior:

• Message regarding failing to find qml2puppet pops up twice

Expected behavior:

• Message comes up only once

Note: For further projects or switching to the Designer view this message comes up only once. You have to restart Creator to get the same behavior again.