Remove generic Exception when using assertRaises
Remove generic Exception when using assertRaises

This change fixes errors associated with H202 checks and enables H202
checks.

Change-Id: I28a48d1b58f2f1f6824ee4b45782a0c961fe9fb5

budnyjj/ofagent,yamt/networking-ofagent-old3,yamt/networking-ofagent,budnyjj/ofagent