Sneaking sideways doesn't add up the x and z speed like java does.

Steps to reproduce bug.
1. login to your world
2. sneak in a diagonal direction/sideways by pressing the s and a/ s and d keys
3. compair speed to sneaking backwards by pressing s key.

expected result: the directional speed of the a/d keys and the directional speed of the s key should be added up.

current result: the speed stays consistant between sneaking sideways and backwards