Update 0xa7-security-misconfiguration.md

Author: inonshk

2019/en/src/0xa7-security-misconfiguration.md

@@ -65,6 +65,9 @@ The API life cycle should include:
   assets (e.g., images).
 * An automated process to continuously assess the effectiveness of the
   configuration and settings in all environments.
+* To prevent exception traces and other valuable information from being sent
+  back to attackers, if applicable, define and enforce all API response payload
+  schemas including error responses.
 
 ## References