don't use zipfile's context manager as it won't work on py2.6

[Ionuț Arțăriși]

Context managers were introduced in the zipfile module in python 2.7[1], so they don't work on py2.6. I noticed this failing unittest on py2.6

[1] http://docs.python.org/library/zipfile.html#zipfile-objects

======================================================================
ERROR: test_ec2_download_view (horizon.dashboards.settings.ec2.tests.EC2SettingsTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/var/lib/openstack-dashboard-test/horizon/dashboards/settings/ec2/tests.py", line 60, in test_ec2_download_view
res = self.client.post(INDEX_URL, data)
File "/usr/lib64/python2.6/site-packages/django/test/client.py", line 449, in post
response = super(Client, self).post(path, data=data, content_type=content_type, **extra)
File "/usr/lib64/python2.6/site-packages/django/test/client.py", line 259, in post
return self.request(**r)
File "/usr/lib64/python2.6/site-packages/django/core/handlers/base.py", line 111, in get_response
response = callback(request, *callback_args, **callback_kwargs)
File "/var/lib/openstack-dashboard-test/horizon/decorators.py", line 40, in dec
return view_func(request, *args, **kwargs)
File "/var/lib/openstack-dashboard-test/horizon/decorators.py", line 57, in dec
return view_func(request, *args, **kwargs)
File "/var/lib/openstack-dashboard-test/horizon/decorators.py", line 40, in dec
return view_func(request, *args, **kwargs)
File "/usr/lib64/python2.6/site-packages/django/views/generic/base.py", line 47, in view
return self.dispatch(request, *args, **kwargs)
File "/usr/lib64/python2.6/site-packages/django/views/generic/base.py", line 68, in dispatch
return handler(request, *args, **kwargs)
File "/var/lib/openstack-dashboard-test/horizon/forms/views.py", line 75, in post
return self.get(self, request, *args, **kwargs)
File "/var/lib/openstack-dashboard-test/horizon/forms/views.py", line 63, in get
form, handled = self.maybe_handle()
File "/var/lib/openstack-dashboard-test/horizon/forms/views.py", line 58, in maybe_handle
self.form, self.handled = form.maybe_handle(self.request, **kwargs)
File "/var/lib/openstack-dashboard-test/horizon/forms/base.py", line 92, in maybe_handle
exceptions.handle(request)
File "/var/lib/openstack-dashboard-test/horizon/forms/base.py", line 90, in maybe_handle
return form, form.handle(request, data)
File "/var/lib/openstack-dashboard-test/horizon/dashboards/settings/ec2/forms.py", line 85, in handle
redirect=request.build_absolute_uri())
File "/var/lib/openstack-dashboard-test/horizon/dashboards/settings/ec2/forms.py", line 76, in handle
with zipfile.ZipFile(temp_zip.name, mode='w') as archive:
AttributeError: ZipFile instance has no attribute '__exit__'

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/5343
Committed: http://github.com/openstack/horizon/commit/53f15d9424bd6137baf98187215520abb6c545cc
Submitter: Jenkins
Branch: master

commit 53f15d9424bd6137baf98187215520abb6c545cc
Author: Ionuț Arțăriși <email address hidden>
Date: Wed Mar 14 17:36:33 2012 +0100

    don't use zipfile's context manager as it won't work on py2.6

    Fixes bug: 955994

    Change-Id: I436c667f496b10d64281538692acc10e327a8fdf