Remove stale config l3|dhcp_agent_manager options

There is no longer a trace of these options anywhere in the
Neutron codebase. These can be safely removed.

Change-Id: Ibf00e158248e2a20248917c8cfc0011d30da6a82
diff --git a/lib/neutron_plugins/linuxbridge_agent b/lib/neutron_plugins/linuxbridge_agent
index 0a06635..67d0405 100644
--- a/lib/neutron_plugins/linuxbridge_agent
+++ b/lib/neutron_plugins/linuxbridge_agent
@@ -44,14 +44,13 @@
 
 function neutron_plugin_configure_dhcp_agent {
     local conf_file=$1
-    iniset $conf_file DEFAULT dhcp_agent_manager neutron.agent.dhcp_agent.DhcpAgentWithStateReport
+    :
 }
 
 function neutron_plugin_configure_l3_agent {
     local conf_file=$1
     sudo brctl addbr $PUBLIC_BRIDGE
     iniset $conf_file DEFAULT external_network_bridge
-    iniset $conf_file DEFAULT l3_agent_manager neutron.agent.l3_agent.L3NATAgentWithStateReport
 }
 
 function neutron_plugin_configure_plugin_agent {
diff --git a/lib/neutron_plugins/openvswitch_agent b/lib/neutron_plugins/openvswitch_agent
index 69e38f4..02eebe1 100644
--- a/lib/neutron_plugins/openvswitch_agent
+++ b/lib/neutron_plugins/openvswitch_agent
@@ -29,13 +29,12 @@
 
 function neutron_plugin_configure_dhcp_agent {
     local conf_file=$1
-    iniset $conf_file DEFAULT dhcp_agent_manager neutron.agent.dhcp_agent.DhcpAgentWithStateReport
+    :
 }
 
 function neutron_plugin_configure_l3_agent {
     local conf_file=$1
     _neutron_ovs_base_configure_l3_agent
-    iniset $conf_file DEFAULT l3_agent_manager neutron.agent.l3_agent.L3NATAgentWithStateReport
 }
 
 function neutron_plugin_configure_plugin_agent {