Make an AppConfig to register ccxcon signals.

openedx/core/djangoapps/ccxcon/__init__.py

@@ -6,4 +6,5 @@ that is used to interact with the CCX and their master courses.
 The ccxcon app needs to be placed in `openedx.core.djangoapps`
 because it will be used both in CMS and LMS.
 """
-import openedx.core.djangoapps.ccxcon.signals
+
+default_app_config = 'openedx.core.djangoapps.ccxcon.apps.CCXConnectorConfig'

openedx/core/djangoapps/ccxcon/apps.py

+"""
+Configuration for CCX connector
+"""
+
+from django.apps import AppConfig
+
+
+class CCXConnectorConfig(AppConfig):
+    name = 'openedx.core.djangoapps.ccxcon'
+    verbose_name = "CCX Connector"
+
+    def ready(self):
+        import openedx.core.djangoapps.ccxcon.signals