Change "secrete" to "secret"

Apparently this is intentional as a joke on devstack leaking
passwords, but the dual meaning of the word confuses people.  Let's
change it before we get yet another review fixing it.

Change-Id: I3bee03612f6ea197362aab04a37f81043f77f235
diff --git a/doc/source/openrc.rst b/doc/source/openrc.rst
index 0b090c7..4e7f075 100644
--- a/doc/source/openrc.rst
+++ b/doc/source/openrc.rst
@@ -35,7 +35,7 @@
 
     ::
 
-        OS_PASSWORD=secrete
+        OS_PASSWORD=secret
 
 HOST\_IP, SERVICE\_HOST
     Set API endpoint host using ``HOST_IP``. ``SERVICE_HOST`` may also