package/libgpg-error: bump to version 1.51
For the changelog, see:
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgpg-error.git;a=log;h=libgpg-error-1.51
Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
[Julien: add link to change log]
Signed-off-by: Julien Olivain <ju.o@free.fr>