There is no such setting.
If a person makes changes to the source while debugging, it is not necessary always the case that the person wants to restart the process.
I have often had that, when it takes a lot of steps to navigate the app to a problematic bit of code. Then when I made one change (could be a comment to an unrelated issue), I still want to continue, and see how the rest works, before I restart.
But what you can do is record an editor macro. ctrl-F2, then F9
Assign it to a new key. You can't use F9, because it will always stop, even if nothing was edited. You still may need F9 to run to the next breakpoint.
http://wiki.lazarus.freepascal.org/IDE_Window:_Editor_Macros