Add PtzPreset to SetPtzPreset POST data

[MJPye]

Hi,
I was using reolinkapi==0.4.1 with an E1 zoom camera and when calling add_preset from ptz.py I got the following error:

[{'cmd': 'SetPtzPreset', 'code': 1, 'error': {'detail': 'not exist', 'rspCode': -1}}]

Which means "Missing Parameters".

Adding PtzPreset to the POST data fixed it for me.

From Camera HTTP API version 5,

PS: Thank you for maintaining this repo, has been super fun to use. I am using an E1 zoom camera mounted on top of a mobile robot :)

[Benehiko]

LGTM