bug#32189: 27.0.50; GCC 7 warning due to -Wformat-truncation=2

[Eli Zaretskii]

> Cc: 32189@debbugs.gnu.org
> From: Ken Brown <kbrown@cornell.edu>
> Date: Wed, 18 Jul 2018 15:42:55 -0400
> 
> On 7/18/2018 11:09 AM, Eli Zaretskii wrote:
> > Do we really need to use -Wformat-truncation?  Is it a useful warning
> > switch?  The above sounds like useless noise, because the code
> > explicitly _asks_ for truncation.  What do people think about this?
> 
> Moreover, the warning isn't very smart; see below.

My vote is for removing this warning until it becomes smarter.  Any
objections, anyone?