Improve ChangeLog wording for the commmit that Fixes Mbed-TLS#1954.

Author: Hanno Becker

ChangeLog

@@ -10,9 +10,11 @@ Bugfix
    * Add ecc extensions only if an ecc based ciphersuite is used.
      This improves compliance to RFC 4492, and as a result, solves
      interoperability issues with BouncyCastle. Raised by milenamil in #1157.
-   * Fix overly strict bounds check in ssl_parse_certificate_request()
-     which could lead to valid CertificateRequest messages being rejected.
-     Fixes #1954.
+   * Fix a bug that caused SSL/TLS clients to incorrectly abort the handshake
+     with TLS versions 1.1 and earlier when the server requested authentication
+     without providing a list of CAs. This was due to an overly strict bounds
+     check in parsing the CertificateRequest message,
+     introduced in Mbed TLS 2.12.0. Fixes #1954.
 
 = mbed TLS 2.1.14 branch released 2018-07-25