Elytraflight + Creative fly incompatability

[spide-r]

Describe the bug Elytraflight (control mode at least, dunno about other modes. makes you drop like a rock if you are in the air and no elytra in your inv / full inventory preventing from an elytra being swapped.

To Reproduce

1. Go into air with fly hacks
2. Have no elytras in your inventory
3. Set to control mode
4. Enable elytra flight
5. Watch yourself fall

Expected behavior Downward movement from the elytra module would either be halted or prevented from occuring.

Additional context I will probably pr this but I just wanna remember to fix before 1.1.7

[5HT2]

User error, don't use creative mode

[spide-r]

User error, don't use creative mode

:wheelchair: still incompatible