Allow turning off CoreEventDispatcher watchdog for debugging.

This can be done by setting CoreManager maxEventTimeLimit=0

Change-Id: I5328677020fe0fd48976957a89ee0a32d1d61292
diff --git a/core/net/src/main/java/org/onosproject/core/impl/CoreManager.java b/core/net/src/main/java/org/onosproject/core/impl/CoreManager.java
index 7b9c705..a8405dd 100644
--- a/core/net/src/main/java/org/onosproject/core/impl/CoreManager.java
+++ b/core/net/src/main/java/org/onosproject/core/impl/CoreManager.java
@@ -183,11 +183,11 @@
         }
 
         Integer timeLimit = Tools.getIntegerProperty(properties, "maxEventTimeLimit");
-        if (timeLimit != null && timeLimit > 1) {
+        if (timeLimit != null && timeLimit >= 0) {
             maxEventTimeLimit = timeLimit;
             eventDeliveryService.setDispatchTimeLimit(maxEventTimeLimit);
         } else if (timeLimit != null) {
-            log.warn("maxEventTimeLimit must be greater than 1");
+            log.warn("maxEventTimeLimit must be greater than or equal to 0");
         }
 
         Boolean performanceCheck = Tools.isPropertyEnabled(properties, "sharedThreadPerformanceCheck");