Remove mention of haproxy-endpoints role

Role was never migrated to usage of haproxy-endpoints role
and included task was used instead the whole time.
With that to reduce complexity and to have unified approach, all mention
of the role and handler are removed from the code.

Change-Id: I27c2ddedc3997d63ddcb08c9f4c06ec1cb287ed1

handlers/main.yml

@@ -42,7 +42,3 @@
   listen:
     - "Restart murano services"
     - "venv changed"
-
-- meta: noop
-  listen: Manage LB
-  when: false

tasks/murano_post_install.yml

@@ -32,6 +32,5 @@
       config_type: "ini"
       config_overrides: "{{ murano_paste_conf_overrides }}"
   notify:
-    - Manage LB
     - Restart murano services
     - Restart uwsgi services