fixup! master: automatically discard feeding cells that get out-of-date

This fixes a random failure in testSafeTweak:

  failureException: 'UU.|U.U|.UU' != 'UU.|.UU|U.U'

neo/tests/threaded/__init__.py

@@ -1025,7 +1025,11 @@ class NEOThreadedTest(NeoTestBase):
         with Patch(client, _getFinalTID=lambda *_: None):
             self.assertRaises(ConnectionClosed, txn.commit)
 
-    def assertPartitionTable(self, cluster, expected, pt_node=None):
+    def assertPartitionTable(self, cluster, expected, pt_node=None,
+                                   sort_by_nid=False):
+        if sort_by_nid:
+            index = lambda x: x
+        else:
             index = [x.uuid for x in cluster.storage_list].index
         super(NEOThreadedTest, self).assertPartitionTable(
             (pt_node or cluster.admin).pt, expected,

neo/tests/threaded/testReplication.py

@@ -421,7 +421,7 @@ class ReplicationTests(NEOThreadedTest):
         s0.resetNode()
         s0.start()
         self.tic()
-        self.assertPartitionTable(cluster, 'UU.|U.U|.UU')
+        self.assertPartitionTable(cluster, 'UU.|U.U|.UU', sort_by_nid=True)
 
     @with_cluster(start_cluster=0, partitions=3, replicas=1, storage_count=3)
     def testReplicationAbortedBySource(self, cluster):