SCBC-491 NPE when managing cluster-level eventing functions

Third parameter of AsyncEventingFunctionManagerShared constructor
is an Option, but caller was passing null.

Change-Id: I85533b9dc5f353d6cef4316550829588f202ce7a
Reviewed-on: https://review.couchbase.org/c/couchbase-jvm-clients/+/228621
Reviewed-by: Graham Pople <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: dnault

scala-client/src/main/scala/com/couchbase/client/scala/manager/eventing/AsyncEventingFunctionManager.scala

@@ -40,7 +40,7 @@ class AsyncEventingFunctionManager(
 ) {
   private[scala] val DefaultTimeout       = env.timeoutConfig.managementTimeout
   private[scala] val DefaultRetryStrategy = env.retryStrategy
-  private val internal                    = new AsyncEventingFunctionManagerShared(env, couchbaseOps, null)
+  private val internal                    = new AsyncEventingFunctionManagerShared(env, couchbaseOps, None)
 
   /** Upsert an eventing function into the admin scope ('*.*').
     *