Update VimeoClient_Async.cs

Patching privacy is 'privacy.view', rather than just 'privacy'. Per spec: https://developer.vimeo.com/api/endpoints/videos#/videos/+clip_id.

I am assuming Vimeo changed their API. Tested and validated.
Merge pull request #4 from Scoobysnax/patch-1

Update VimeoClient_Async.cs