Merge remote-tracking branch 'origin/pr/1818' into mbedtls-2.16

* origin/pr/1818:
  Move ChangeLog entry from Bugfix to Changes section
  Adapt ChangeLog
  Return from debugging functions if SSL context is unset
diff --git a/ChangeLog b/ChangeLog
index 9b8dd47..a11bab0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -59,6 +59,8 @@
      been disabled for lack of a sufficiently recent version of GnuTLS on the CI.
    * Ciphersuites based on 3DES now have the lowest priority by default when
      they are enabled.
+   * Return from various debugging routines immediately if the
+     provided SSL context is unset.
 
 = mbed TLS 2.16.0 branch released 2018-12-21