Delete abortion joke

[Florian Weimer]

> I propose the following patch, which deletes the abortion joke from the 
> glibc manual.

I'm not sure if it was intended as a joke.  People quite literally
believe such things.

I think we can remove the note because it's not in one of the formally
Invariant Sections, so let's do it.

I believe you don't have commit access yourself.  Should I push this
along with a suitable ChangeLog entry?

We should also clean up the language regarding the risk of
distributing cryptography code.