Description of problem:

If you sync a repo with an errata that does not have a package list such as this one here:

https://github.com/Katello/runcible/blob/master/test/fixtures/repositories/zoo5/updateinfo.xml#L3-L9

and then try to generate applicability for a consumer, you will get an error:

  File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/profilers/yum.py", line 314, in _is_errata_applicable
    errata_rpms = YumProfiler._get_rpms_from_errata(errata)
  File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/profilers/yum.py", line 292, in _get_rpms_from_errata
    for pkgs in errata.metadata['pkglist']:
TypeError: 'NoneType' object is not iterable

and the applicability is not generated for that client.

Version-Release number of selected component (if applicable):
6.3

How reproducible:
Always

Steps to Reproduce:
1. git checkout https://github.com/Katello/runcible/
2. sync the repo in runcible/test/fixtures/repositories/zoo5
3. register a client and assign it to the product created for step #2
4. the applicability should get generated for this client and you should see a traceback in /var/log/messages indicating a failure

Actual results:
traceback, applicability isn't generated

Expected results:
no traceback, applicability is generated

Additional info: