Use proper section name in httpd.filterClass example

Change-Id: I0f28f509d96a748782a2b720d0c0f551f8b57d7b
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index 01d92c6..ca567d1 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -2070,7 +2070,7 @@
 	type = HTTP
 	httpHeader = TRUSTED_USER
 
-[http]
+[httpd]
 	filterClass = org.anyorg.MySecureFilter
 ----