Avoid conflicts with other tests instances

Avoid conflicts with other instances that exist, for example when
weren't deleted in other tests. Just filter out them in test that
check instances amount by server IDs

Closes-Bug: #1340382
Change-Id: I51494c9f47745810583f682caadcd8772805733a
diff --git a/tempest/api/compute/servers/test_list_server_filters.py b/tempest/api/compute/servers/test_list_server_filters.py
index f66020c..9d39c9f 100644
--- a/tempest/api/compute/servers/test_list_server_filters.py
+++ b/tempest/api/compute/servers/test_list_server_filters.py
@@ -203,11 +203,13 @@
         params = {'status': 'active'}
         resp, body = self.client.list_servers_with_detail(params)
         servers = body['servers']
+        test_ids = [s['id'] for s in (self.s1, self.s2, self.s3)]
 
         self.assertIn(self.s1['id'], map(lambda x: x['id'], servers))
         self.assertIn(self.s2['id'], map(lambda x: x['id'], servers))
         self.assertIn(self.s3['id'], map(lambda x: x['id'], servers))
-        self.assertEqual(['ACTIVE'] * 3, [x['status'] for x in servers])
+        self.assertEqual(['ACTIVE'] * 3, [x['status'] for x in servers
+                                          if x['id'] in test_ids])
 
     @test.attr(type='gate')
     def test_list_servers_filtered_by_name_wildcard(self):