Clarify documentation of ssl_set_own_cert()

fixes #507
diff --git a/ChangeLog b/ChangeLog
index 513f24f..149e439 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,8 @@
      invalidated keys of a lifetime of less than a 1s. Fixes #1968.
    * Fix failure in hmac_drbg in the benchmark sample application, when
      MBEDTLS_THREADING_C is defined. Found by TrinityTonic, #1095
+   * Clarify documentation of mbedtls_ssl_set_own_cert() regarding the absence
+     of check for certificate/key matching. Reported by Attila Molnar, #507.
 
 Changes
    * Add tests for session resumption in DTLS.