python-axolotl has been failing since March,
https://hydra.gnu.org/job/gnu/master/python-axolotl-0.1.35.x86_64-linux
This also fixes the OMEMO and OTR plugins for Gajim work.
* gnu/packages/patches/python-axolotl-AES-fix.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/python-crypto.scm (python-axolotl): Upgrade to 0.1.39.
[source]: Use the patch.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>