Flying through movement-slowing blocks in spectator and changing to survival outputs warning

This probably relates to the other spectator-related hitbox bugs (MC-279016, MC-279021, MC-279031, MC-279032, MC-279033).

Steps to reproduce:

1. Place a cobweb.
2. Enter spectator mode and turn your flying speed up to the maximum.
3. Fly through the cobweb.
4. Enter survival mode.
5. "<Player> moved wrongly!" warning gets outputted in the console (might not always happen).