Fix: cookie doesn't get properly deleted on Firefox.
Fix: cookie doesn't get properly deleted on Firefox.

copyliu/osmium,wffurr/osmium,wffurr/osmium,osmium-org/osmium,copyliu/osmium,wffurr/osmium,wffurr/osmium,copyliu/osmium,osmium-org/osmium,osmium-org/osmium,osmium-org/osmium