Fix wording of ChangeLog and 3DES_REMOVE docs

include/mbedtls/config.h

@@ -695,6 +695,13 @@
  * to enable (some of) them with mbedtls_ssl_conf_ciphersuites() by including
  * them explicitly.
  *
+ * A man-in-the browser attacker can recover authentication tokens sent through
+ * a TLS connection using a 3DES based cipher suite (see "On the Practical
+ * (In-)Security of 64-bit Block Ciphers" by Karthikeyan Bhargavan and Gaëtan
+ * Leurent, see https://sweet32.info/SWEET32_CCS16.pdf). If this attack falls
+ * in your threat model or you are unsure, then you should keep this option
+ * enabled to remove 3DES based cipher suites.
+ *
  * Comment this macro to keep 3DES in the default ciphersuite list.
  */
 #define MBEDTLS_REMOVE_3DES_CIPHERSUITES