Update for ChangeLog for fixes for cert_app
diff --git a/ChangeLog b/ChangeLog
index 61152e9..ee6c1f9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -48,6 +48,7 @@
      when GCM is used. #441
    * Fix for key exchanges based on ECDH-RSA or ECDH-ECDSA which weren't
      enabled unless others were also present. Found by David Fernandez. #428
+   * Fixed configuration of debug output in cert_app sample program.
 
 = mbed TLS 1.3.17 branch 2016-06-28