3.3.0: Possible regression in cygwin DLL (Win10); fixed in snapshot

[Brian]

GCM (Git Credential Manager) - Core fails to properly authenticate with
previously stored credentials under the latest 3.3.0 release version of the
Cygwin DLL (the bug itself and steps to recreate was originally submitted
to the GCM-Core team here:
https://github.com/microsoft/Git-Credential-Manager-Core/issues/509).  By
replacing the Cygwin DLL with the 0913 snapshot, the problem no longer
occurs. One of the GCM-Core devs suggested it might be a regression issue
in the DLL.  Unfortunately, I don't have the C chops to explore this
further.

  --Brian