src: rename namespace as chronochat

Change-Id: Idf390b1b2047c912735014d078ce099cf95026e6
diff --git a/src/intro-cert-list.proto b/src/intro-cert-list.proto
index 6b65a83..b365aa4 100644
--- a/src/intro-cert-list.proto
+++ b/src/intro-cert-list.proto
@@ -1,4 +1,4 @@
-package Chronos;
+package chronochat;
 
 message IntroCertListMsg
 {