"@bors rollup+" should work

[RalfJung]

I can never remember whether the syntax for marking something as rolled-up is rollup or rollup+. Some things get a + after them to be enabled (such as delegate+), some don't (such as rollup), so the syntax is inconsistent and it's hard to remember which command uses which syntax.

What about just accepting both bors rollup and bors rollup+ and have them mean the same thing? Then at least it doesn't matter when one cannot remember.