Fix datatype for query statistics (close #802)

Change-Id: I44120df02524c2ea8d75c8a78b625f46b6aa8863
diff --git a/Changes b/Changes
index 58194d9..0cec767 100644
--- a/Changes
+++ b/Changes
@@ -3,6 +3,7 @@
 - Implement timeout rewrite
 - Add a test: changing timeout using a pipe
 - Add pipe response rewriting (#794)
+- Fix datatype for query statistics (close #802)
 
 # version 0.78.2