libdnf: resolve cstdint inclusion for newer gcc versions

libdnf: resolve cstdint inclusion for newer gcc versions

Depending on the host gcc version, libdnf fails to compile due to
missing cstdint inclusions. These issue have already been addressed
upstream, add the patches to resolve this for older versions of the
library.

These commits are taken directly from the libdnf project at
https://github.com/rpm-software-management/libdnf

Signed-off-by: Abe Kohandel <abe.kohandel@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>