1862 Fix checkpoint read permission

[Nic-Ma]

Fixes #1862 .

Description

This PR fixed the read permission issue of checkpoint, based on suggestion from @vfdev-5 in pytorch/ignite#1876.

Status

Ready

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Integration tests passed locally by running ./runtests.sh -f -u --net --coverage.
• Quick tests passed locally by running ./runtests.sh --quick --unittests.
• In-line docstrings updated.
• Documentation updated, tested make html command in the docs/ folder.

[Nic-Ma]

/black

[wyli]

thanks, we'll revert this after the upstream fix release