[ANNOUNCE] NSPR 4.38 Release

[Kai Engert]

The NSPR 4.38 release is now available. The hg tag is
NSPR_4_38_RTM. The source tar file can be downloaded from
https://ftp.mozilla.org/pub/mozilla.org/nspr/releases/v4.38/src/

NSPR 4.38 contains the following changes:

- Removed support for HPUX and _PR_POLL_WITH_SELECT.
- Fixed a bug in pt_TCP_SendTo on macOS
- Ensure parameter passed to isalpha() is unsigned char.

For more details, please refer to the list of related bugs:
https://bugzilla.mozilla.org/buglist.cgi?resolution=FIXED&query_format=advanced&product=NSPR&target_milestone=4.38

Thanks to all contributors to this release.

Kai