Re-enable test_check_smtp_pool test

Story: #2000773

Change-Id: I66a813b133b8c594e5d46f31f3add114708d8063
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index 5b97e53..e24c72a 100755
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -3003,10 +3003,8 @@
             self.assertEqual(len(self.builds), 0)
             self.assertEqual(len(self.history), x * 2)
 
-    @skip("Disabled for early v3 development")
     def test_check_smtp_pool(self):
-        self.updateConfigLayout(
-            'tests/fixtures/layout-smtp.yaml')
+        self.updateConfigLayout('layout-smtp')
         self.sched.reconfigure(self.config)
 
         A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')