Changing visiblity settings applies to incorrect post

[kopecs]

On occasion when changing the visibility setting for a post, the change is applied to the previously viewed post.

To reproduce:

• Select a post (A) in the post office
• Select another post (B) in the post office
• Change the visibility of that post (B)

Expected behaviour: visibility of B is changed.
Actual outcome: visibility of A is changed.

[umutacar]

Should be fixed