more error-prone issue fix

Change-Id: I49f2cc0459cfddddc6a99e2ebb8ad52d547e2909
diff --git a/apps/tetopology/app/src/test/java/org/onosproject/tetopology/management/DefaultBuilder.java b/apps/tetopology/app/src/test/java/org/onosproject/tetopology/management/DefaultBuilder.java
index 47cdcd6..1c82fcc 100644
--- a/apps/tetopology/app/src/test/java/org/onosproject/tetopology/management/DefaultBuilder.java
+++ b/apps/tetopology/app/src/test/java/org/onosproject/tetopology/management/DefaultBuilder.java
@@ -143,7 +143,7 @@
         for (long i = 0; i < numTtps; i++) {
             ttps.put(i, ttpBuilder(i));
         }
-        ttp = ttps.get(FIRST_INDEX);
+        ttp = ttps.get((long) FIRST_INDEX);
         //TeNode
         teNode = new DefaultTeNode(teNodeId, underlayTopologyId,
                                    supportTeNodeId, sourceTeNodeId,