[others with access] duplicate entries on level 0

[wiswedel]

Steps to reproduce

1. User A shares Foo with User B
2. User A shares Foo/Bar with User C
3. User A opens sidebar for Foo/Bar
4. User C appears in the list of sharees for Foo/Bar
5. User A clicks on Others with Access

Expected behaviour

User B appears as other with access.

Actual behaviour

User B and User C appear as others with access, even though User C is already listed in this object's sharee list.

[ChristophWurst]

@daita?

[ArtificialOwl]

this fix only the fact that shares in current folder will not be displayed within the inherited shares. However, if Foo/ was shared to UserC, the share would be displayed in the inherited shares.