apps/web: fix reset error on next step

apps/web/context/form-state.tsx

@@ -20,6 +20,7 @@ const reducer = (state: State, action: Action): State => {
       if (action.payload.step)
         return {
           ...state,
+          error: undefined,
           step: action.payload.step,
           user: action.payload.user || state.user,
         };