openSUSE Leap 42.1: 2015:2257-1 Important Heap Corruption Fix

This update for mbedtls fixes the following security and non-security

issues:

- Update to 1.3.15

* Fix potential double free if ssl_set_psk() is called more than once

and some allocation fails. Cannot be forced remotely. Found by Guido

Vranken, Intelworks.

* Fix potential heap corruption on windows when x509_crt_parse_path() is

passed a path longer than 2GB. Cannot be triggered remotely. Found by

Guido Vranken, Intelworks.

* Fix potential buffer overflow in some asn1_write_xxx() functions.

Cannot be triggered remotely unless you create X.509 certificates based

on untrusted input or write keys of untrusted origin. Found by Guido

Vranken, Intelworks.

* The x509 max_pathlen constraint was not enforced on intermediate

certificates. Found by Nicholas Wilson, fix and tests provided by

Janos Follath. #280 and #319

* Self-signed certificates were not excluded from pathlen counting,

...