Add reference to original PR in Changelog
@@ -6,7 +6,7 @@ Bugfix
* Fix possible memory leak in mbedtls_ssl_config_free().
This can occur only if the user doesn't use mbedtls_ssl_conf_psk() and
instead incorrectly manipulates conf->psk and/or conf->psk_identity
- directly. Fix submitted by junyeonLEE.
+ directly. Found and fix submitted by junyeonLEE in #1220.
= mbed TLS 2.7.x branch released 2018-xx-xx
