Follow the above advice
is your safest bet.
If you wanted to visit the site even against the alerts, by going to shield control and disable for 10 minutes, you are disabling 'all' shields, to you have zero protection at all. So that is something you shouldn't do.
Whilst it is possible this may be an FP, disabling all shields is like playing Russian roulette, some time there will be a bullet opposite the chamber. If it is an FP then the investigation of the site will reveal that and something can be done to resolve it; this benefits all avast users.
As for a setting, it entirely depends on what shield is blocking, Network or Web Shield and that is why we need more information.