Update zuul-changes.py doc to match usage

zuul-changes.py does not accept --review-host param
since 574ec76a6085b13fb1f02697e68baea7cc0bb63b

It's usage output is:
usage: zuul-changes.py [-h] url pipeline_name

Correct the docs to match.

Change-Id: Iab8158f73f6b1611d088377e36a7d076907bf8f6
diff --git a/doc/source/zuul.rst b/doc/source/zuul.rst
index 9be4deb..6c77477 100644
--- a/doc/source/zuul.rst
+++ b/doc/source/zuul.rst
@@ -1092,13 +1092,11 @@
 If you need to abort Zuul and intend to manually requeue changes for
 jobs which were running in its pipelines, prior to terminating you can
 use the zuul-changes.py tool script to simplify the process. For
-example, this would give you a list of Gerrit commands to reverify or
-recheck changes for the gate and check pipelines respectively::
+example, this would give you a list of zuul-enqueue commands to requeue
+changes for the gate and check pipelines respectively::
 
-  ./tools/zuul-changes.py --review-host=review.openstack.org \
-      http://zuul.openstack.org/ gate 'reverify'
-  ./tools/zuul-changes.py --review-host=review.openstack.org \
-      http://zuul.openstack.org/ check 'recheck'
+  ./tools/zuul-changes.py http://zuul.openstack.org/ gate
+  ./tools/zuul-changes.py http://zuul.openstack.org/ check
 
 If you send a SIGUSR2 to the zuul-server process, or the forked process
 that runs the Gearman daemon, Zuul will dump a stack trace for each