oslo.config will begin to enfore types in a future version

Early versions of oslo.config allowed any type when overriding a config
setting. Future versions of oslo.config will default to enforcing the
type[1]. This changes silences the deprecation warning by passing the
proper value type to override.

[1] https://review.openstack.org/#/c/365476/

Change-Id: Ie9fd8f0b8e9b75492854e22e4f169ac56cfd548d

networking_arista/tests/unit/l3Plugin/test_arista_l3_driver.py

@@ -26,10 +26,10 @@ def setup_arista_config(value='', vrf=False, mlag=False):
     cfg.CONF.set_override('primary_l3_host', value, "l3_arista")
     cfg.CONF.set_override('primary_l3_host_username', value, "l3_arista")
     if vrf:
-        cfg.CONF.set_override('use_vrf', value, "l3_arista")
+        cfg.CONF.set_override('use_vrf', vrf, "l3_arista")
     if mlag:
         cfg.CONF.set_override('secondary_l3_host', value, "l3_arista")
-        cfg.CONF.set_override('mlag_config', value, "l3_arista")
+        cfg.CONF.set_override('mlag_config', mlag, "l3_arista")
 
 
 class AristaL3DriverTestCasesDefaultVrf(base.BaseTestCase):