Crouching doesn't properly uncrouch in multiplayer

[Cervator]

When crouching in multiplayer everything is fine if you're the host - but if you are a connected client and attempt to crouch you sort of get stuck vibrating slightly and rapidly up and down, even long after no longer crouching. Something in the process does not seem to terminate correctly when purely a client. Maybe you get stuck in a crouch/uncrouch loop.

You can "fix" the issue temporarily by flying / ghosting as that gets you ungrounded, at which point you are incapable of crouching. But the issue returns after you land and takes logging out then back in to solve permanently.

[gianluca-nitti]

For reference, here is a gif showing the bug: http://imgur.com/a/K83Jn

[oniatus]

Closing as proposed in #2961 (comment)
(Issue should be fixed with the PR)
Follow up issue is #1075