Don't crash after Cancel in Job Already Running dialog
When a user Execute-Launches an application a second time while the previously launched instance of this application is still running, the "Job Already Running" dialog appears with 3 buttons. If a user clicks the Cancel button, a NativeAppJob kills itself Quietly. This NativeAppJob belongs to an ExecuteCompositeJob, which is not notified when a subjob is killed Quietly. So the ExecuteCompositeJob keeps waiting for it to finish. When this waiting ExecuteCompositeJob is killed (e.g. via "Stop All" button or on KDevelop exit), it attempts to kill the subjob it believes is still running, but which in fact is long since destroyed. This usually causes a segmentation fault.
Aleix Pol fixed a similar crash when the "Kill All Instances" button in the "Job Already Running" dialog is clicked in 8430d305.
FIXED-IN: 5.6.1