Update update-settings.asciidoc

Removed deprecated `cluster.routing.allocation.disable` settings

Author: clintongormley

docs/reference/cluster/update-settings.asciidoc

@@ -100,21 +100,6 @@ due to forced awareness or allocation filtering.
        allowed cluster wide, and default it to `2` (integer). `-1` for 
        unlimited. See also <<modules-cluster>>.
 
-[float]
-===== Disable allocation
-
-All the disable allocation settings have been deprecated in favour for
-`cluster.routing.allocation.enable` setting.
-
-`cluster.routing.allocation.disable_allocation`::
-     See <<modules-cluster>>.
-
-`cluster.routing.allocation.disable_replica_allocation`::
-     See <<modules-cluster>>.
-
-`cluster.routing.allocation.disable_new_allocation`::
-     See <<modules-cluster>>.
-
 [float]
 ===== Enable allocation