User card going under PM header

[Ellibereth]

See:

[jomaxro (Joshua Rosenfeld)]

@awesomerobot this is what I mentioned to you the other day.

[awesomerobot (Kris)]

Looks like it’s just a z-index issue, here’s a fix

https://github.com/discourse/discourse/commit/411512c0e375dd33ec17b18c61ec936c637544d6