[Helper] Remove ejabberd from compose

helper-scripts/docker-compose.override.yml.d/BUILD_FLAGS/docker-compose.override.yml

@@ -42,6 +42,3 @@ services:
 
   olefy-mailcow:
     build: ./data/Dockerfiles/olefy
-
-  ejabberd-mailcow:
-    build: ./data/Dockerfiles/ejabberd