Stop disabling the Neutron tempest plugin

The root cause for the Inspector grenade failures was an eventlet
monkey patch[1]. The issue now being solved, disabling the Neutron
tempest plugin is no longer necessary.

[1] https://review.openstack.org/#/c/399469/

Closes-bug: #1621791
Change-Id: Icaca019880054e1d89b81736c2815a222e8abc45
diff --git a/ironic_tempest_plugin/plugin.py b/ironic_tempest_plugin/plugin.py
index 218f100..0428c7d 100644
--- a/ironic_tempest_plugin/plugin.py
+++ b/ironic_tempest_plugin/plugin.py
@@ -13,7 +13,6 @@
 
 import os
 
-from oslo_config import cfg
 from tempest.test_discover import plugins
 
 from ironic_inspector.test.inspector_tempest_plugin import config
@@ -33,10 +32,6 @@
         conf.register_group(config.baremetal_introspection_group)
         conf.register_opts(config.BaremetalIntrospectionGroup,
                            group="baremetal_introspection")
-        if os.path.exists('/tmp/ironic-inspector-grenade'):
-            # FIXME(dtantsur): pretend like Neutron does not exist due to
-            # random failures, see https://bugs.launchpad.net/bugs/1621791.
-            cfg.CONF.set_override('neutron', False, 'service_available')
 
     def get_opt_lists(self):
         return [