Fix Blocker Bug - prevent from npe throwing

Change-Id: Id6dd23c07f282ac7c7d3df3f612175d1bbf5a184
Issue-ID: SO-2187
Signed-off-by: Lukasz Muszkieta <lukasz.muszkieta@nokia.com>
diff --git a/bpmn/so-bpmn-tasks/src/main/java/org/onap/so/bpmn/infrastructure/workflow/tasks/WorkflowAction.java b/bpmn/so-bpmn-tasks/src/main/java/org/onap/so/bpmn/infrastructure/workflow/tasks/WorkflowAction.java
index 78cb533..e6dd38e 100644
--- a/bpmn/so-bpmn-tasks/src/main/java/org/onap/so/bpmn/infrastructure/workflow/tasks/WorkflowAction.java
+++ b/bpmn/so-bpmn-tasks/src/main/java/org/onap/so/bpmn/infrastructure/workflow/tasks/WorkflowAction.java
@@ -372,7 +372,7 @@
                 }
             }
 
-            if (flowsToExecute.isEmpty()) {
+            if (flowsToExecute == null || flowsToExecute.isEmpty()) {
                 throw new IllegalStateException("Macro did not come up with a valid execution path.");
             }
             List<String> flowNames = new ArrayList<>();