Fix typo in documentation of LDAP_BIND authentication

Change-Id: Ib4b1aff5b044d0813b900cc65c0ed4ffdc9c21ed
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index a57c8a7..8e85b6d 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -141,7 +141,7 @@
 is not involved in the user authentication process.
 +
 Unlike `LDAP` above, the username used to perform the LDAP simple bind
-request is the exact string supplied by in the dialog by the user.
+request is the exact string supplied in the dialog by the user.
 The configured <<ldap.username,ldap.username>> identity is not used to obtain
 account information.
 +