tests should only run when applicable for adv-sg zone in such env

##### ISSUE TYPE

* Documentation Report
* testing/CI

##### COMPONENT NAME

~~~
marvin
~~~

##### CLOUDSTACK VERSION

~~~
4.18
~~~

##### CONFIGURATION

~~~
advanced zone with security groups.
~~~

##### OS / ENVIRONMENT

##### SUMMARY

when an advanced zone with security groups is used to test for regressions, a lot of errors occur.
an example
```
ERROR: test suite for
----------------------------------------------------------------------
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 210, in run
self.setUp()
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 293, in setUp
self.setupContext(ancestor)
File "/usr/local/lib/python3.6/site-packages/nose/suite.py", line 316, in setupContext
try_run(context, names)
File "/usr/local/lib/python3.6/site-packages/nose/util.py", line 471, in try_run
return func()
File "/marvin/tests/smoke/test_router_dns.py", line 92, in setUpClass
zoneid=cls.zone.id)
File "/usr/local/lib/python3.6/site-packages/marvin/lib/base.py", line 3562, in create
return Network(apiclient.createNetwork(cmd).__dict__)
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackAPI/cloudstackAPIClient.py", line 2981, in createNetwork
response = self.connection.marvinRequest(command, response_type=response, method=method)
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 381, in marvinRequest
raise e
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 376, in marvinRequest
raise self.__lastError
File "/usr/local/lib/python3.6/site-packages/marvin/cloudstackConnection.py", line 310, in __parseAndGetResponse
response_cls)
File "/usr/local/lib/python3.6/site-packages/marvin/jsonHelper.py", line 155, in getResultObj
raise cloudstackException.CloudstackAPIException(respname, errMsg)
marvin.cloudstackException.CloudstackAPIException: Execute cmd: createnetwork failed, due to: errorCode: 431, errorText:Only shared guest network can be created in security group enabled zone
```

this is not necessary as we know beforehand that these tests will fail.
Tests need to be properly tagged to not run in these environments.

##### STEPS TO REPRODUCE

~~~

~~~

##### EXPECTED RESULTS

~~~
test will not run
~~~

##### ACTUAL RESULTS

~~~
test runs and fails
~~~

Comienza con marvin/tests/smoke/test_router_dns.py y la configuración de TestRouterDns mostrada en el informe; después inspecciona las demás pruebas de regresión que fallan en una zona avanzada con grupos de seguridad. La tarea estará terminada cuando las pruebas que no sean aplicables en este entorno se omitan en lugar de ejecutarse y fallar; verifica el comportamiento con el conjunto de pruebas afectado.

Escrito por el modelo de indexación a partir del texto del issue.