Updated Misc/NEWS with #17508.
Issue #17521: Corrected non-enabling of logger following two calls to fileConfig().
Fixes issue #17488: Change the subprocess.Popen bufsize parameter default value
from unbuffered (0) to buffering (-1) to match the behavior existing code
expects and match the behavior of the subprocess module in Python 2 to avoid
introducing hard to track down bugs.
Clean up references to threads in test_queue.