Remove duplicate lbaas provider config

Option `service_provider` is defined in neutron_lbaas.conf, there
is a duplicated config option in neutron.conf, it should be removed
there. Otherwise neutron-server will not be able to start with error:
'Invalid: Driver
neutron_lbaas.drivers.haproxy.plugin_driver.HaproxyOnHostPluginDriver is
not unique across providers'

Change-Id: I3fc379535eb00bbcb23aa41de95ca8161883a181
Closes-bug: #1625174

ansible/roles/neutron/templates/neutron.conf.j2

@@ -50,11 +50,6 @@ transport_url = rabbit://{% for host in groups['rabbitmq'] %}{{ rabbitmq_user }}
 router_distributed = True
 {% endif %}
 
-{% if enable_neutron_lbaas | bool %}
-[service_providers]
-service_provider = LOADBALANCERV2:Haproxy:neutron_lbaas.drivers.haproxy.plugin_driver.HaproxyOnHostPluginDriver:default
-{% endif %}
-
 [nova]
 auth_url = {{ keystone_admin_url }}
 auth_type = password