Check for null on PV Table item get method

Author: tynanford

app/pvtable/src/main/java/org/phoebus/applications/pvtable/ui/TableItemProxy.java

@@ -82,6 +82,10 @@ public TableItemProxy()
 
     public PVTableItem getItem()
     {
+        if(item == null)
+        {
+            return null;
+        }
         return item.get();
     }