fixe a bug with rerun

src/jflow/workflow.py

@@ -242,9 +242,10 @@ class Workflow(threading.Thread):
         """
         Only require for Threading
         """
-        # first init the component list within the workflow
-        self.init_component_nameids()
-        self.start_time = time.time()
+        # if this is the first time the workflow run
+        if self.start_time == None :
+            self.init_component_nameids()
+            self.start_time = time.time()
         self.status = self.STATUS_STARTED
         self.end_time = None  
         # serialize the workflow before pre processing