[ONOS-6118] Revert default number of threads in FlowObjectiveManager to 4

Change-Id: I6035c5a497947b67023da92c591f51f24a5bf314
diff --git a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
index c14471a..d9aca56 100644
--- a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
+++ b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
@@ -87,7 +87,7 @@
 
     private final Logger log = LoggerFactory.getLogger(getClass());
 
-    private static final int DEFAULT_NUM_THREADS = 1;
+    private static final int DEFAULT_NUM_THREADS = 4;
     @Property(name = NUM_THREAD,
              intValue = DEFAULT_NUM_THREADS,
              label = "Number of worker threads")