Hello, thank you for your rating. Unfortunately it is not my signature that is missing, but a general certificate failure on Mozilla's side that affected all Firefox extensions from all authors. You can find more details at https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/ .
To solve the problem, make sure to update to the latest Firefox version, and if ReloadMatic doesn't get re-enabled automatically (Mozilla claims this might happen to some users), then try reintalling the extension after the Firefox update. Let me know if you still have problems then.