Being inmortal cause of wrong version

[neiionyc 0]

*What you were doing: Playing

*Current installed version: 1.7.1.1 and beta 93825

*Server(s) you were on: Servers with 1.7 and beta 93825 (yeah, outdated)

*Timeline of events before/after error: I joined an outdated server accidentally, and i realized i was inmortal, i could pick items and they got saved when i logged in a server that had the last version. Also the "mismatch of version" was almost invisible so i realized i was in the outdated server after i couldn't get damage.

Tested it with another outdated server and the same happened

The point is that i don't want people to exploit that (me included), so solving it would be nice.