Document default replication delay

Change-Id: I792efbd2ac1ca68f3a18b680bc014b31cb9ed81a

setup_local_env/README.md

diff --git a/setup_local_env/README.md b/setup_local_env/README.md
index e6ec9e7..8d9665f 100644
--- a/setup_local_env/README.md
+++ b/setup_local_env/README.md
@@ -74,7 +74,7 @@
 [--gerrit2-httpd-port]          Gerrit Instance 2 http port; default 18081
 [--gerrit2-sshd-port]           Gerrit Instance 2 sshd port; default 49418
 
-[--replication-delay]           Replication delay across the two instances in seconds
+[--replication-delay]           Replication delay across the two instances in seconds; default 5 seconds
 
 [--just-cleanup-env]            Cleans up previous deployment; default false