^^
............ that kinda sucked.
V.
No it doesn't. You can still do the backward roll in MP (haven't tried SP).
The fact is, that you can't simply hold the key and do it the same as the forward and side rolls (actually for repeated rolls you have to continuously tap the keys anyway for those too).
You have to either be running for a bit or jump first to then perform the backward roll.
So it's not as easy to simply roll backwards all over the place, but it's still possible to do it.
Yes it sucks anyway to change it in the server options?
Unknown. But you could use the recently released SDK to modify the source to make it how you want it...