schema: re-generate from tdlib master (v1.8.4)

[mxmCherry]

I did it for myself to get message reactions. Confirmed to be working fine with go.mod + replace to local checkout + TDLib master=v1.8.4.

I used master because TDLib devs don't tag patch versions: https://github.com/tdlib/td/issues/1818#issuecomment-1044841985

~~I did not check if it still works with 1.8.0 (the tagged version) though - hopefully it still works.~~

Works with v1.8.4 and v1.8.0 - checked with listener.Updates.

~~But still not sure if "write" methods (send message etc) still work with v1.8.0.~~

SendMessage with plain text message works in v1.8.0 as well.

So this change looks to be back-compatible (unless new methods/features are used with older tdlib).