Security level is using an unsafe getBoolPref

read_setting_from_prefs:

      const wanted = kSecuritySettings[prefName][settingIndex];
      const actual = Services.prefs.getBoolPref(prefName);
      if (wanted !== actual) {
        possibleSetting = false;
        logger.debug(
          `${prefName} does not match level ${settingIndex}: ${actual}, should be ${wanted}!`
        );
        break;
      }

However, getBoolPref might throw.

We need to wrap that in a try/catch and maybe issue a warning when encountered.