Update changes.src

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
diff --git a/doc/changes.src b/doc/changes.src
index 6aeb276..5e7bf06 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -9,6 +9,8 @@
 
 \S{cl-2.09} Version 2.09
 
+\b Fixed NULL dereference if environment variable is missed.
+
 \b Updates of new AVX v7 Intel instruciotns.
 
 \b \c{PUSH imm32} is now officially documented.