Fix docs test

docs/reference/indices/shrink-index.asciidoc

@@ -63,10 +63,19 @@ the following request:
 [source,js]
 --------------------------------------------------
 POST my_source_index/_shrink/my_target_index?copy_settings=true
+{
+  "settings": {
+    "index.routing.allocation.require._name": null, <1>
+    "index.blocks.write": null <2>
+  }
+}
 --------------------------------------------------
 // CONSOLE
 // TEST[continued]
 
+<1> Clear the allocation requirement copied from the source index.
+<2> Clear the index write block copied from the source index.
+
 The above request returns immediately once the target index has been added to
 the cluster state -- it doesn't wait for the shrink operation to start.