Accidentally removed confirmation before closing multiple tabs

[QuadCore]

Hello there.
I've accidentally ticked "don't show again" when I was asked if I am sure I wan't to close multiple tabs. I tried to find it in settings, but there was nothing about it. I also found relative string in preferences file and tried setting it to true or deletting it, but it got overwritten after browser launch.
Please help me to get this useful feature back on 

[Admin]

The option is located at "Tab options"->"Warn me when closing window with multiple tabs".

[QuadCore]

CentBrowser, thanks. Found it.