Update Ansible scheduler instructions (#5224)

* Removed extraneous instruction

Akka dispatcher added directly into code in recent commit so this is no longer necessary

* Add directions for scheduler without elasticsearch

Author: hunhoffe

ansible/README.md

@@ -157,6 +157,8 @@ It will run one more component called "scheduler" and ETCD.
 You can update service providers for the scheduler as follows. 
 
 **common/scala/src/main/resources/reference.conf**
+
+If you are using ElasticSearch (recommended) then replace ```NoopDurationCheckerProvider``` with ```ElasticSearchDurationCheckerProvider``` below.
 ```
 whisk.spi {
   ArtifactStoreProvider = org.apache.openwhisk.core.database.CouchDbStoreProvider
@@ -169,27 +171,13 @@ whisk.spi {
   AuthenticationDirectiveProvider = org.apache.openwhisk.core.controller.BasicAuthenticationDirective
   InvokerProvider = org.apache.openwhisk.core.invoker.FPCInvokerReactive
   InvokerServerProvider = org.apache.openwhisk.core.invoker.FPCInvokerServer
-  DurationCheckerProvider = org.apache.openwhisk.core.scheduler.queue.ElasticSearchDurationCheckerProvider
+  DurationCheckerProvider = org.apache.openwhisk.core.scheduler.queue.NoopDurationCheckerProvider
 }
 .
 .
 .
 ```
 
-#### Configure akka dispatcher for the scheduler
-Add a new dispatcher entry as follows.
-
-**common/scala/src/main/resources/reference.conf**
-```
-  lease-service-dispatcher {
-    executor = "thread-pool-executor"
-    type = PinnedDispatcher
-  }
-.
-.
-.
-```
-
 #### Enable the scheduler
 - Make sure you enable the scheduler by configuring `scheduler_enable`.