Fix blocks not being correctly cleared on logout

See, this refactor is where omissions like this that normally would pass
unnoticed stop passing unnoticed.

Author: bdach

osu.Game/Online/API/LocalUserState.cs

@@ -75,6 +75,7 @@ public void ClearLocalUser()
                 localUser.Value = createGuestUser();
                 configSupporter.Value = false;
                 friends.Clear();
+                blocks.Clear();
             });
         }