[models] Updated sortedm2m __str__ definition

Author: nemesifier

openwisp_controller/config/models.py

@@ -5,7 +5,7 @@
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 from django_netjsonconfig.base.config import TemplatesVpnMixin as BaseMixin
-from django_netjsonconfig.base.config import AbstractConfig, sortedm2m__str__
+from django_netjsonconfig.base.config import AbstractConfig, TemplatesThrough
 from django_netjsonconfig.base.device import AbstractDevice
 from django_netjsonconfig.base.tag import AbstractTaggedTemplate, AbstractTemplateTag
 from django_netjsonconfig.base.template import AbstractTemplate
@@ -83,6 +83,7 @@ class Config(OrgMixin, TemplatesVpnMixin, AbstractConfig):
     templates = SortedManyToManyField('config.Template',
                                       related_name='config_relations',
                                       verbose_name=_('templates'),
+                                      base_class=TemplatesThrough,
                                       blank=True,
                                       help_text=_('configuration templates, applied from '
                                                   'first to last'))
@@ -100,9 +101,6 @@ def clean(self):
         super(Config, self).clean()
 
 
-Config.templates.through.__str__ = sortedm2m__str__
-
-
 class TemplateTag(AbstractTemplateTag):
     """
     openwisp-controller TemplateTag model

requirements.txt

@@ -1,2 +1,2 @@
-django-netjsonconfig>=0.6.3,<0.7.0
+django-netjsonconfig>=0.6.4,<0.7.0
 openwisp-utils[users]<0.2