Makes the `SystemConfig` able to be initialized again.
It previously couldn't be because of a strict require statement
on a state variable that was set in a previous time that the
contract was initialized.

A full upgrade simulation using this implementation can be found here:
https://dashboard.tenderly.co/public/safe/safe-apps/simulator/e2d907e4-d5cb-4034-ae32-4b73d655cedf?trace=0.0.0.4.0.13.0