Update Filter Parser for 3.21

[shakesx]

3.21 filters from Filterblade are not able to be uploaded to the app - says 'Errors found while parsing filter'. I am assuming this is because of the new items added in 3.21.

If possible, could an update be made so the latest filters from this league are compatible?

[Qt-dev]

It is actually most likely due to something way earlier since this has not been updated in a while. I am working on getting that 1.0 out, and may redo that filter part once I get to it. Thank you for your report!