This is not a false widow. It is an Amaurobius species, there are 2 or 3 common ones, A. ferox is a likely candidate. As with any bite/sting keep an eye on it for signs of infection, the venom itself is unlikely to have any long lasting effect.
It's an amaurobiid, Amaurobius ferox I think. The only spider that's ever bitten me was another Amaurobius species and apart from the pinprick-like bite which produced a small red mark I wasn't badly affected, in terms of visible symptoms or discomfort.