Log Message:
Update to 1.3.9. Make it build with new libgnutls (which don't have the
libgnutls-config script any more).

Changes since 1.3.7:

* Preallocate and only copy the string once when escaping or unescaping it.
* Try to open both IPv6 and IPv4 listening sockets. This is required in
  case bindtov6only is 1 to also accept IPv4 connections in IPv6 mode.