Client seems to desync very frequently when using reacharound (seems most prominent when using horizontal reacharound, but it's also the one I use the most).

It happens very often (probably for more than 1% of block placed) with a server running on the same machine as the client.
As expected from that kind of desynced, it causes the client to get booted for flying when preventflying is enabled, or just ignores every new placement based on the desynced blocks otherwise.

Causes potentially huge structures to be desynced since reacharound is often used to make 1 wide bridges.

Dupe of #2628