Sulfur Cubes do not properly calculate knockback direction when hit by swimming players

Steps to Reproduce:

1. Get a sulfur cube in water

2. Put any wooden block inside of it

3. Hit it from below while swimming

Observed Results:
The Sulfur Cube gets a big horizontal knockback.

Expected Resuts:
The Sulfur Cube gets a big vertical knockback, similar to how it behaves when hit by standing players.

Screenshots/Videos attached: Yes

Notes: