Session not saved on quit via SIGTERM

Context: If one quits SpeedCrunch via menu (Session > Quit) or via shortcut (Ctrl + Q), the current session will be saved as expected and restored the next time one starts up SpeedCrunch.

Bug description: But if one kills SpeedCrunch via sending a SIGTERM signal (i.e. $ killall -s 9 speedcrunch) the session will not be saved and in turn not restored.

Expected behavior: SpeedCrunch should behave the same, no matter how one quits it.