load.FlowModLoad: shuffle flow-mods before sending them to the switch

This should cover more code paths than the previous pattern.
diff --git a/tests/load.py b/tests/load.py
index 3295fd5..66487cb 100644
--- a/tests/load.py
+++ b/tests/load.py
@@ -14,9 +14,8 @@
 """
 
 import copy
-
+import random
 import logging
-
 import unittest
 
 from oftest import config
@@ -239,6 +238,7 @@
             self.checkBarrier()
 
             logging.info("Iteration %d: add %s flows" % (i, num_flows))
+            random.shuffle(requests)
             for request in requests:
                self.assertNotEqual(self.controller.message_send(request), -1,
                                "Error installing flow mod")