bug in gc-des module

[Bruno Haible]

The des_setkey function still collides with the one on MacOS X:

gcc -DHAVE_CONFIG_H -I. -I../../../megatestdir/gc-des/lib -I..     -g -O2 -c 
../../../megatestdir/gc-des/lib/gc-gnulib.c
In file included from ../../../megatestdir/gc-des/lib/gc-gnulib.c:65:
../../../megatestdir/gc-des/lib/des.h:62: error: conflicting types for 
`des_setkey'
/usr/include/unistd.h:196: error: previous declaration of `des_setkey'
make[4]: *** [gc-gnulib.o] Error 1

Bruno