Sharing the share folder itself shouldn't be allowed

[ishank011]

The Shares folder itself can be shared with other users as well as publically - it is only when the recipient tries to access it that it returns an error. There's a PR to handle it in reva cs3org/reva#1051, but it should be prevented by phoenix in the first place.

[diocas]

@ishank011 I think we can close this. We no longer can share the shares folder (and we even want to hide it). Please re-open if not true.