XFCE4 Terminal how to enable quit warning for multiple tabs open & tasks running

[kamui]

Hello, guys!
I accidentally checked the box for disabling the quit warning for xfce4 terminal when tasks aren't done. How can I enable it back?

EDIT:
I should reformulate.
My terminal was popping up a Warning window which asked if I really want to close my terminal session when multiple tabs are open or if i want to quit when there's an on-going task.
Below is the behaviour before checking the box.


I accidentally checked the box with Don't ask me again and now my terminal doesn't pop up that Warning anymore.
How can I enable it back?