[BUG] REX pretraversals are failing.
### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

 REX pretraversals are failing.

### Expected Behavior

 REX pretraversals should work

### Steps To Reproduce

create a n entity with a relationship an attempt to explore from it from the REX UI.

### Environment

```markdown
- Egeria:
- OS:
- Java:
- Browser (for UI issues):
- Additional connectors and integration:
```


### Any Further Information?

The Traversal logic work on longs whereas the pre traversal logic is incorrectly working with Longs (the object) and it checks for non null to determine if there is an asOfTime. The value is 0 for this case so it fails if the back end repository does no support asOfTime on the query 
diff --git a/open-metadata-implementation/view-services/rex-view/rex-view-server/src/main/java/org/odpi/openmetadata/viewservices/rex/handlers/RexViewHandler.java b/open-metadata-implementation/view-services/rex-view/rex-view-server/src/main/java/org/odpi/openmetadata/viewservices/rex/handlers/RexViewHandler.java
index 39e4d6ba87..a618422571 100644
--- a/open-metadata-implementation/view-services/rex-view/rex-view-server/src/main/java/org/odpi/openmetadata/viewservices/rex/handlers/RexViewHandler.java
+++ b/open-metadata-implementation/view-services/rex-view/rex-view-server/src/main/java/org/odpi/openmetadata/viewservices/rex/handlers/RexViewHandler.java
@@ -979,7 +979,7 @@ public class RexViewHandler
                                         boolean         enterpriseOption,
                                         String          entityGUID,
                                         int             depth,
-                                        Long            asOfTime,
+                                        long            asOfTime,
                                         String          methodName)
     throws
     RexViewServiceException
@@ -1021,7 +1021,7 @@ public class RexViewHandler
             if (depth > 0)
             {
                 Date asOfTimeDate = null;
-                if (asOfTime !=null) {
+                if (asOfTime != 0) {
                     asOfTimeDate = new Date(asOfTime);
                 }
                 instGraph = repositoryServicesClient.getEntityNeighborhood(userId,
['open-metadata-implementation/view-services/rex-view/rex-view-server/src/main/java/org/odpi/openmetadata/viewservices/rex/handlers/RexViewHandler.java']