This reverts commits 9aecb00947 and
cdad5961f3 which fixed a different
compiler warning that seems to have disappeared (at least on the
debian-8-full builds).
* lib/md5.c include/md5.h: added md5 functions from GNU textutils
* include/sane/sanei_auth.h sanei/sanei_auth.c: implemented new
SANE interface for user authorization using MD5 digest