Reduced durability when gliding on Elytra

Put the summary of the bug you're having here

What I expected to happen was...:
Durability does not decrease when glide with Elytra.
What actually happened was...:
Reduced durability when gliding on Elytra.

Steps to Reproduce:
1. wear Elytra.
2. Gliding
3. Decrease Durability of the Elytra.