Missing Configuration Key

OPC v2.4.1 (apparently)

@lat9, re the issue raised on Github OPC, I see that you referred to the 'Payment Methods Handling Form Submittal' configuration switch introduced in OPC v2.4.0

Even though I have been upgrading through the versions to v2.4.1, I don't have that setting in my admin but I see that the code to add it is in init_checkout_one_upgrade.php, can you suggest a way for me to manually add or re-run that SQL code to add this setting and perhaps also check for any others that might be missing?

I don't usually muck up my upgrades, for some reason OPC has been my bugbear.