Fix assertions when we catch an error in the tests

Code that is within a `with Python.raises(...)` context manager but
comes after the line that raises the exception doesn't get evaluated.
We had some assertions that we never being tested because of this, so
this ensures that they will always get run and fixes them where
necessary.

tests/app/celery/test_ftp_update_tasks.py

@@ -182,7 +182,7 @@ def test_update_letter_notifications_to_error_updates_based_on_notification_refe
     with freeze_time(dt):
         with pytest.raises(NotificationTechnicalFailureException) as e:
             update_letter_notifications_to_error([first.reference])
-            assert first.reference in e.value
+    assert first.reference in str(e.value)
 
     assert first.status == NOTIFICATION_TECHNICAL_FAILURE
     assert first.sent_by is None

tests/app/celery/test_letters_pdf_tasks.py

@@ -681,7 +681,7 @@ def test_process_letter_task_check_virus_scan_error(sample_letter_notification,
     with pytest.raises(VirusScanError) as e:
         process_virus_scan_error(filename)
 
-    assert "Virus scan error:" in str(e)
+    assert "Virus scan error:" in str(e.value)
     mock_move_failed_pdf.assert_called_once_with(filename, ScanErrorType.ERROR)
     assert sample_letter_notification.status == NOTIFICATION_TECHNICAL_FAILURE
 

tests/app/celery/test_nightly_tasks.py

@@ -194,7 +194,7 @@ def test_update_status_of_notifications_after_timeout(notify_api, sample_templat
                 seconds=current_app.config.get('SENDING_NOTIFICATIONS_TIMEOUT_PERIOD') + 10))
         with pytest.raises(NotificationTechnicalFailureException) as e:
             timeout_notifications()
-            assert str(not2.id) in e.value
+        assert str(not2.id) in str(e.value)
         assert not1.status == 'temporary-failure'
         assert not2.status == 'technical-failure'
         assert not3.status == 'temporary-failure'

tests/app/celery/test_provider_tasks.py

@@ -65,7 +65,7 @@ def test_should_go_into_technical_error_if_exceeds_retries_on_deliver_sms_task(s
 
     with pytest.raises(NotificationTechnicalFailureException) as e:
         deliver_sms(sample_notification.id)
-        assert sample_notification.id in e.value
+    assert str(sample_notification.id) in str(e.value)
 
     provider_tasks.deliver_sms.retry.assert_called_with(queue="retry-tasks", countdown=0)
 
@@ -78,7 +78,7 @@ def test_should_go_into_technical_error_if_exceeds_retries_on_deliver_email_task
 
     with pytest.raises(NotificationTechnicalFailureException) as e:
         deliver_email(sample_notification.id)
-        assert sample_notification.id in e.value
+    assert str(sample_notification.id) in str(e.value)
 
     provider_tasks.deliver_email.retry.assert_called_with(queue="retry-tasks")
     assert sample_notification.status == 'technical-failure'