Clarify 3DES changes in ChangeLog
diff --git a/ChangeLog b/ChangeLog
index 4e03774..d768ccc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,7 +42,8 @@
    * Ensure that ssl-opt.h can be run in OS X. #2029
    * Reduce the complexity of the timing tests. They were assuming more than the
      underlying OS actually guarantees.
-   * Ciphersuites based on 3DES now have the lowest priority by default.
+   * Ciphersuites based on 3DES now have the lowest priority by default when
+     they are enabled.
 
 = mbed TLS 2.16.0 branch released 2018-12-21