unregister also when phonenumber plugin app is no longer installed (fixes #663)

Author: jpaniagualaconich

two_factor/plugins/phonenumber/apps.py

@@ -1,4 +1,4 @@
-from django.apps import AppConfig
+from django.apps import AppConfig, apps
 from django.conf import settings
 from django.test.signals import setting_changed
 
@@ -12,19 +12,21 @@ class TwoFactorPhoneNumberConfig(AppConfig):
     url_prefix = 'phone'
 
     def ready(self):
-        register_methods(self, None, None)
-        setting_changed.connect(register_methods)
+        updated_registered_methods(self, None, None)
+        setting_changed.connect(updated_registered_methods)
 
 
-def register_methods(sender, setting, value, **kwargs):
+def updated_registered_methods(sender, setting, value, **kwargs):
     # This allows for dynamic registration, typically when testing.
     from .method import PhoneCallMethod, SMSMethod
 
-    if getattr(settings, 'TWO_FACTOR_CALL_GATEWAY', None):
+    phone_number_app_installed = apps.is_installed('two_factor.plugins.phonenumber')
+
+    if phone_number_app_installed and getattr(settings, 'TWO_FACTOR_CALL_GATEWAY', None):
         registry.register(PhoneCallMethod())
     else:
         registry.unregister('call')
-    if getattr(settings, 'TWO_FACTOR_SMS_GATEWAY', None):
+    if phone_number_app_installed and getattr(settings, 'TWO_FACTOR_SMS_GATEWAY', None):
         registry.register(SMSMethod())
     else:
         registry.unregister('sms')