Workaround for old compiler

- Was failing on eclise built-in compiler

Change-Id: Ifd76449d0c1054876e447603aa3aff982c3a5e52
diff --git a/core/store/dist/src/main/java/org/onosproject/store/newresource/impl/ConsistentResourceStore.java b/core/store/dist/src/main/java/org/onosproject/store/newresource/impl/ConsistentResourceStore.java
index a51baa7..a6c3e57 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/newresource/impl/ConsistentResourceStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/newresource/impl/ConsistentResourceStore.java
@@ -213,7 +213,8 @@
                         return lookup(childTxMap, x);
                     }
                 })
-                .flatMap(Tools::stream)
+                .filter(Optional::isPresent)
+                .map(Optional::get)
                 .collect(Collectors.toList());
         // the order is preserved by LinkedHashMap
         Map<DiscreteResourceId, List<Resource>> resourceMap = resources.stream()