Remove unused SUBDOMAIN_BRANDING setting from edxapp config

CHANGELOG.md

+- Role: edxapp
+  - Removed SUBDOMAIN_BRANDING and SUBDOMAIN_COURSE_LISTINGS variables
+
 - Role: ora
   - Remove the ora1 role as support for it was deprecated in Cypress.
   - Removed dependencies on ora throughout the playbooks / vagrantfiles.

playbooks/roles/edxapp/defaults/main.yml

@@ -179,7 +179,6 @@ EDXAPP_FEATURES:
   CERTIFICATES_ENABLED: true
   ENABLE_DISCUSSION_SERVICE: true
   ENABLE_INSTRUCTOR_ANALYTICS: false
-  SUBDOMAIN_BRANDING: false
   PREVIEW_LMS_BASE: "{{ EDXAPP_PREVIEW_LMS_BASE }}"
   ENABLE_S3_GRADE_DOWNLOADS: true
   USE_CUSTOM_THEME: "{{ edxapp_use_custom_theme }}"
@@ -394,8 +393,7 @@ EDXAPP_CODE_JAIL_LIMITS:
   PROXY: 0
 
 EDXAPP_VIRTUAL_UNIVERSITIES: []
-EDXAPP_SUBDOMAIN_BRANDING: {}
-# Set the number of workers explicitely for lms and cms
+# Set the number of workers explicitly for lms and cms
 # Should be set to
 # EDXAPP_WORKERS:
 #   lms: <num workers>
@@ -826,7 +824,6 @@ generic_env_config:  &edxapp_generic_env
   FILE_UPLOAD_STORAGE_BUCKET_NAME: "{{ EDXAPP_FILE_UPLOAD_STORAGE_BUCKET_NAME }}"
   FILE_UPLOAD_STORAGE_PREFIX: "{{ EDXAPP_FILE_UPLOAD_STORAGE_PREFIX }}"
   VIRTUAL_UNIVERSITIES: "{{ EDXAPP_VIRTUAL_UNIVERSITIES }}"
-  SUBDOMAIN_BRANDING: "{{ EDXAPP_SUBDOMAIN_BRANDING }}"
   REGISTRATION_EXTRA_FIELDS: "{{ EDXAPP_REGISTRATION_EXTRA_FIELDS }}"
   XBLOCK_SETTINGS: "{{ EDXAPP_XBLOCK_SETTINGS }}"
   EDXMKTG_USER_INFO_COOKIE_NAME: "{{ EDXAPP_EDXMKTG_USER_INFO_COOKIE_NAME }}"