Don't delete containment if appletDelete is on one of children
Systemtray incorrectly emits appletDeleted on the systray cntainment for the children, make sure that is really the applet emitting appletDeleted on itself
(cherry picked from commit 0d3e3f28)
0d3e3f28 Don't delete containment if appletDelete is on one of children
Co-authored-by: Marco Martin notmart@gmail.com