libgcrypt: bump to 1.4.5

Also autotools.in conversion and change source location from
gd.tuwien.ac.at to ftp.gnupg.org

[Peter: add missing libgpg-error makefile dependency]
Signed-off-by: Lionel Landwerlin <llandwerlin@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>