Late addition of subscriber (basically after two eapols) results in voltha error

If you do a successful authentication, and don't do a volt_add_subscriber right after, but wait till a second successful authentication and then add the subscriber flows, voltha complains with

20190618T233314.505 ERROR MainThread openolt_flow_mgr.repush_all_different_flows

{'exception': 'Traceback (most recent call last):\n File "/voltha/voltha/adapters/openolt/openolt_flow_mgr.py", line 1101, in repush_all_different_flows\n self.add_flow(logical_flow)\n File "/voltha/voltha/adapters/openolt/openolt_flow_mgr.py", line 287, in add_flow\n "tp-updates-not-supported"\nAssertionError: tp-updates-not-supported', 'e': AssertionError('tp-updates-not-supported',), 'ip': '192.168.100.111:9191', 'instance_id': 'vcore-0_1560899524', 'vcore_id': '0001', 'event': 'Problem reading this flow'}

This test was done without pushing any tech profile into etcd