[texhax] Obsolete \centerline command used in amsbook class

[Philip TAYLOR]

Uwe Lück wrote:

> I tend to recommend deprecation of l2tabu, or even banning it.
> Don't tell adult people what to do and not to do!;)
> It is bold and somewhat annoying.

L2TABU, like all rules, exists solely for the guidance of the
wise and the blind obedience of the foolish.

Philip Taylor