Fix issue #21641: Close the socket before raising the SMTPResponseException. Fixes the ResourceWarning in the test run.

Patch by Claudiu.Popa.
merge from 3.4

Fix issue #21641: Close the socket before raising the SMTPResponseException. Fixes the ResourceWarning in the test run.
Patch by Claudiu.Popa.
Issue #21439: Fix a couple of typos.
Issue #21439: Merge with 3.4
Issue #21643: Updated test and fixed logic bug in lib64 symlink creation.
Closes #21643: Merged fix from 3.4.
All modern compilers provide a offsetof() function

offsetof() is used directly in many other .c files without any issue.