batches: tweak wording of superseding batch spec banner
Created by: LawnGnome
Dealing with the big issues today. The wording of this message doesn't quite work for me, since it ends up like:
A modified batch spec was uploaded 24 days ago, but has not been applied.
I think this reads better.
Test plan
Verified with a Mark I eyeball. (I suspect we've disabled the snapshot that would have included this, but we'll see what CI does.)