Merge #14465: tests: Stop node before removing the notification file

ca6d86c tests: Stop node before removing the notification file (Chun Kuan Lee)

Pull request description:

  Stop node before removing the notification file to make sure the command has been terminated. After then we could removing those files safely and do not receive any permission error. (See #14446)

  The permission error is Windows specific, documented in python doc:
  >On Windows, attempting to remove a file that is in use causes an exception to be raised

  See https://docs.python.org/3/library/os.html#os.remove

Tree-SHA512: fbdabf3a9a838bb59ba207dd9e9fbdd87c702a99ad66bee0b2b1537f80f8630d22d9d5e9c4ded23a82a66bfc10989227fb024b27393425abe0e5a2ad4e4cbb82

Author: sipa

test/functional/feature_notifications.py

@@ -51,12 +51,13 @@ def run_test(self):
             # directory content should equal the generated transaction hashes
             txids_rpc = list(map(lambda t: t['txid'], self.nodes[1].listtransactions("*", block_count)))
             assert_equal(sorted(txids_rpc), sorted(os.listdir(self.walletnotify_dir)))
+            self.stop_node(1)
             for tx_file in os.listdir(self.walletnotify_dir):
                 os.remove(os.path.join(self.walletnotify_dir, tx_file))
 
             self.log.info("test -walletnotify after rescan")
             # restart node to rescan to force wallet notifications
-            self.restart_node(1)
+            self.start_node(1)
             connect_nodes_bi(self.nodes, 0, 1)
 
             wait_until(lambda: len(os.listdir(self.walletnotify_dir)) == block_count, timeout=10)