USN-4973-2: Python vulnerability

USN-4973-2: Python vulnerability

USN-4973-1 fixed this vulnerability previously, but it was re-introduced
in python3.8 in focal because of the SRU in LP: #1928057. This update fixes
the problem.

Original advisory details:

It was discovered that the Python stdlib ipaddress API incorrectly handled
octal strings. A remote attacker could possibly use this issue to perform a
wide variety of attacks, including bypassing certain access restrictions.
Source: USN-4973-2: Python vulnerability