Upgrade to Pynac-0.7.24

[rwst]

0.7.24 fixes behaviour under Python 3 (Jeroen Demeyer)

https://github.com/pynac/pynac/releases/download/pynac-0.7.24/pynac-0.7.24.tar.bz2

CC: @jdemeyer

Component: packages: standard

Author: Ralf Stephan

Branch: a6ceab9

Reviewer: Marc Mezzarobba

Issue created by migration from https://trac.sagemath.org/ticket/27241

[rwst]

Branch: u/rws/upgrade_to_pynac_0_7_24

[rwst]

New commits:

a6ceab9

pynac-0.7.24 pkg/chksum

[rwst]

Commit: a6ceab9

[rwst]

Author: Ralf Stephan

[mezzarobba]

Reviewer: Marc Mezzarobba

[vbraun]

Changed branch from u/rws/upgrade_to_pynac_0_7_24 to a6ceab9