Fix deprecation warnings when unpickling pynac objects with Python 3.8

[antonio-rojas]

With Python 3.8, unpickling pynac objects gives a deprecation warning

DeprecationWarning: PY_SSIZE_T_CLEAN will be required for '#' formats

These are fixed in this ticket by defining PY_SSIZE_T_CLEAN where appropriate

Upstream pull request: pynac/pynac#354

Upstream: Reported upstream. No feedback yet.

CC: @jhpalmieri @mkoeppe

Component: packages: standard

Author: Antonio Rojas

Branch/Commit: ecc6f45

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/30225

[antonio-rojas]

Description changed:

--- 
+++ 
@@ -1 +1,9 @@
+With Python 3.8, unpickling pynac objects gives a deprecation warning
 
+```
+DeprecationWarning: PY_SSIZE_T_CLEAN will be required for '#' formats
+```
+
+These are fixed in this ticket by defining PY_SSIZE_T_CLEAN where appropriate
+
+Upstream pull request: https://github.com/pynac/pynac/pull/354

[antonio-rojas]

Upstream: Reported upstream. No feedback yet.

[antonio-rojas]

Author: Antonio Rojas

[antonio-rojas]

Branch: u/arojas/fix_deprecation_warnings_when_unpickling_pynac_objects_with_python_3_8

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

c4769bf

Add pynac patch to fix deprecation warnings on unpickling with Python 3.8

[sagetrac-git]

Commit: c4769bf

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

ecc6f45

Add patch

[sagetrac-git]

Changed commit from c4769bf to ecc6f45

[mkoeppe]

comment:6

Is this safe to apply also for earlier Python versions?

[antonio-rojas]

comment:7

At least for 3.7 it seems so