ChangeLog.md: List CVE ID fixed by 1719d12e

Referring to https://bugzilla.redhat.com/show_bug.cgi?id=1937385#c2,
it is my opinion that the severity of this bug was grossly overstated
and that a CVE never should have been assigned to it, but since one was
assigned, users need to know which version of libjpeg-turbo contains
the fix.

Dear security community, please learn what "DoS" actually means and stop
misusing that term for dramatic effect.  Thanks.
diff --git a/ChangeLog.md b/ChangeLog.md
index 61a9095..67d1950 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -15,9 +15,9 @@
 encoders to generate incorrect results when using the Clang compiler with
 Visual Studio.
 
-4. Fixed a floating point exception that occurred when attempting to compress a
-specially-crafted malformed GIF image with a specified image width of 0 using
-cjpeg.
+4. Fixed a floating point exception (CVE-2021-20205) that occurred when
+attempting to compress a specially-crafted malformed GIF image with a specified
+image width of 0 using cjpeg.
 
 
 2.0.90 (2.1 beta1)