Log Message:
Update to 5.55

* Change MASTER_SITES to https://

Changelog:
Version 5.55, 2019.06.10, urgency: HIGH
* Security bugfixes
  - Fixed a Windows local privilege escalation vulnerability
    caused insecure OpenSSL cross-compilation defaults.
    Successful exploitation requires stunnel to be deployed
    as a Windows service, and user-writable C:\ folder. This
    vulnerability was discovered and reported by Rich Mirch.
  - OpenSSL DLLs updated to version 1.1.1c.
* Bugfixes
  - Implemented a workaround for Windows hangs caused by its
    inability to the monitor the same socket descriptor from
    multiple threads.
  - Windows configuration (including cryptographic keys)
    is now completely removed at uninstall.
  - A number of testing framework fixes and improvements.

Version 5.54, 2019.05.15, urgency: LOW
* New features
  - New "ticketKeySecret" and "ticketMacSecret" options
    to control confidentiality and integrity protection
    of the issued session tickets.  These options allow
    for session resumption on other nodes in a cluster.
  - Added logging the list of active connections on
    SIGUSR2 or with Windows GUI.
  - Logging of the assigned bind address instead of the
    requested bind address.
* Bugfixes
  - Service threads are terminated before OpenSSL cleanup
    to prevent occasional stunnel crashes at shutdown.

Version 5.53, 2019.04.10, urgency: HIGH
* New features
  - Android binary updated to support Android 4.x.
* Bugfixes
  - Fixed data transfer stalls introduced in stunnel 5.51.

Version 5.52, 2019.04.08, urgency: HIGH
* Bugfixes
  - Fixed a transfer() loop bug introduced in stunnel 5.51.