bug#11494: Accidental format string prevents translation

[Ivan Vilata i Balaguer]

Hi, in coreutils 8.17 (and in current git), `fmt.c` contains the following
help line:

    -g, --goal=WIDTH          goal width (default of 93% of width)

The percent is interpreted (at least by `msgfmt`) as the start of a `%o`
format string, thus translations are forced to have an "o" after `93%` which
makes things quite difficult. ;)

Changing `93%` by `93%%` should do the job.  Thanks,

-- 
Ivan Vilata i Balaguer -- https://elvil.net/