Description of problem:

Update the errata field using TestRun.update() has no effect. This
is caused by a copy-and-paste typo in the update() code.

Actual results:

> [INFO] Updating test run TR#6757
> [DEBUG] {'build': 111,
>  'default_tester': 2117,
>  'errata_id': 111,   <------------------------------------
>  'estimated_time': '00:00:00',
>  'manager': 2117,
>  'notes': 'Testing notes',
>  'product': 61,
>  'status': 1,
>  'summary': 'Tessst Run One'}
> [INFO] Fetching test run TR#6757
> [DEBUG] Initializing test run TR#6757
> [DEBUG] {'build': 'RHEL5.3-Server-20081211.0 : x86_64',
>  'build_id': 111,
>  'case_run_status': '2:2,3:1,6:1,8:1',
>  'cc': [],
>  'default_tester': 'psplicha',
>  'default_tester_id': 2117,
>  'env_value': [],
>  'environment_id': 0,
>  'errata_id': None,   <-----------------------------------
>  'estimated_time': '00:00:00',
>  'manager': 'psplicha',
>  'manager_id': 2117,
>  'notes': 'Testing notes',
>  'plan': 'Tessst plan',
>  'plan_id': 289,
>  'plan_text_version': 1,
>  'product_version': '5.7',
>  'run_id': 6757,
>  'start_date': '2009-12-15 16:33:09',
>  'stop_date': '2012-06-13 17:02:07',
>  'summary': 'Tessst Run One',
>  'tag': []}