Fix ChangeLog entry for issue #1663

The ChangeLog entry was under the wrong version, and under Changes, not
Bug Fixes.
diff --git a/ChangeLog b/ChangeLog
index 7449c89..f8a8f33 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,13 +17,12 @@
      by Brendan Shanks. Part of a fix for #992.
    * Fix compilation error when MBEDTLS_ARC4_C is disabled and
      MBEDTLS_CIPHER_NULL_CIPHER is enabled. Found by TrinityTonic in #1719.
+   * Added length checks to some TLS parsing functions. Found and fixed by
+     Philippe Antoine from Catena cyber. #1663.
 
 Changes
    * Change the shebang line in Perl scripts to look up perl in the PATH.
      Contributed by fbrosson in #1533.
-   * Adds of lengths checks in different functions (not a security issue as
-     original buffer is overgrown) thanks to Philippe Antoine from Catena
-     cyber. #1663.
 
 = mbed TLS 2.1.13 branch released 2018-06-18