update docs to use nova_metadata_host

nova_metadata_ip is deprecated in favor of nova_metadata_host. This
patch updates our docs to use the latter matching our intent on removing
the former.

Change-Id: I6a8e76acc2f01541f92123e46987b0f2f0fbf1cd
Closes-Bug: #1669955

doc/source/admin/deploy-lb-provider.rst

@@ -191,7 +191,7 @@ Compute nodes
    .. code-block:: ini
 
       [DEFAULT]
-      nova_metadata_ip = controller
+      nova_metadata_host = controller
       metadata_proxy_shared_secret = METADATA_SECRET
 
    The value of ``METADATA_SECRET`` must match the value of the same option

doc/source/admin/deploy-ovs-provider.rst

@@ -200,7 +200,7 @@ Compute nodes
    .. code-block:: ini
 
       [DEFAULT]
-      nova_metadata_ip = controller
+      nova_metadata_host = controller
       metadata_proxy_shared_secret = METADATA_SECRET
 
    The value of ``METADATA_SECRET`` must match the value of the same option

doc/source/install/controller-install-obs.rst

@@ -223,7 +223,7 @@ such as credentials to instances.
 
        [DEFAULT]
        # ...
-       nova_metadata_ip = controller
+       nova_metadata_host = controller
        metadata_proxy_shared_secret = METADATA_SECRET
 
     .. end

doc/source/install/controller-install-rdo.rst

@@ -223,7 +223,7 @@ such as credentials to instances.
 
        [DEFAULT]
        # ...
-       nova_metadata_ip = controller
+       nova_metadata_host = controller
        metadata_proxy_shared_secret = METADATA_SECRET
 
     .. end

doc/source/install/controller-install-ubuntu.rst

@@ -220,7 +220,7 @@ such as credentials to instances.
 
        [DEFAULT]
        # ...
-       nova_metadata_ip = controller
+       nova_metadata_host = controller
        metadata_proxy_shared_secret = METADATA_SECRET
 
     .. end