Removed on tick handler, GUI update bug was fixed in 2.0

[kabelmeister]

This handler is just eating away at UPS since the filter GUI update bug was fixed in 2.0. Figured it isn't necessary anymore and removed it.

[Quezler]

Actually that's just a leftover comment from the 2.0 porting, i had the same thought as you but i recall how it was back in the day, as you can see here the part that it referred to is already gone since:

3ebcb73

This pull request should instead change the remaining code into an on_nth_tick(60 thing since the update every second is still used for polling in case the available/suggest items change, which is still important.