Edit business unit fails if there is no machine group

[thomas-dam]

Reproduce:
Clean installation of Sal.
Create new business unit
Edit business unit.

Expected:
Should be able to correct name of business unit.

Result:

Request Method: GET
Request URL: http://REDACTED/business_unit/edit/1/

Django Version: 1.10
Python Version: 2.7.6
Installed Applications:
('django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.sites',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.admin',
 'django.contrib.admindocs',
 'sal',
 'server',
 'api',
 'catalog',
 'inventory',
 'licenses',
 'bootstrap3',
 'watson',
 'datatableview',
 'search')
Installed Middleware:
('django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'server.middleware.AddToBU.AddToBU',
 'search.current_user.CurrentUserMiddleware')

Template loader postmortem
Django tried loading these templates, in this order:

Using engine django:
    * django.template.loaders.filesystem.Loader: /home/docker/sal/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.filesystem.Loader: /home/docker/sal/server/plugins/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.filesystem.Loader: /home/docker/sal/plugins/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /usr/local/lib/python2.7/dist-packages/django/contrib/auth/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /usr/local/lib/python2.7/dist-packages/django/contrib/admin/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /usr/local/lib/python2.7/dist-packages/django/contrib/admindocs/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/server/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/inventory/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/licenses/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /usr/local/lib/python2.7/dist-packages/bootstrap3/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/watson/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/datatableview/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)
    * django.template.loaders.app_directories.Loader: /home/docker/sal/search/templates/{'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>} (Source does not exist)



Traceback:

File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/exception.py" in inner
  39.             response = get_response(request)

File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in _legacy_get_response
  249.             response = self._get_response(request)

File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in _get_response
  187.                 response = self.process_exception_by_middleware(e, request)

File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in _get_response
  185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/usr/local/lib/python2.7/dist-packages/django/contrib/auth/decorators.py" in _wrapped_view
  23.                 return view_func(request, *args, **kwargs)

File "/home/docker/sal/server/views.py" in edit_business_unit
  827.     return render('forms/edit_business_unit.html', c)

File "/usr/local/lib/python2.7/dist-packages/django/shortcuts.py" in render
  30.     content = loader.render_to_string(template_name, context, request, using=using)

File "/usr/local/lib/python2.7/dist-packages/django/template/loader.py" in render_to_string
  67.         template = get_template(template_name, using=using)

File "/usr/local/lib/python2.7/dist-packages/django/template/loader.py" in get_template
  25.     raise TemplateDoesNotExist(template_name, chain=chain)

Exception Type: TemplateDoesNotExist at /business_unit/edit/1/
Exception Value: {'business_unit': <BusinessUnit: TestUnit>, 'form': <EditUserBusinessUnitForm bound=False, valid=Unknown, fields=(name;users)>}

Workaround.
Creare machine group before editing business unit.

[grahamgilbert]

Fixed in c9931de