Ubuntu OVAL response has invalid timestamps

[crozzy]

Ubuntu has just updated their OVAL database with an entry that references an invalid timestamp and means the updaters fail for a number of Ubuntu releases (focal, bionic).

Example snippet from Ubuntu OVAL XML response:

                    ...
                    <public_date>2021-07-19 12:00:00 PT</public_date>
                    <public_date_at_usn>2021-07-19 12:00:00 PT</public_date_at_usn>
                    <assigned_to>mdeslaur</assigned_to>
                    <crd>2021-07-19 12:00:00 PT</crd>
                    ...

Error from the library:

unable to decode string as datestamp: \"2021-07-19 12:00:00 PT\"