Merge bitcoin#14413: tests: Allow closed rpc handler in assert_start_…

…raises_init_error

62c304e tests: Allow closed http server in assert_start_raises_init_error (Chun Kuan Lee)

Pull request description:

  The rpc handler may be unregistered when http server haven't been closed yet. So it may be allowable to get -342 `non-JSON HTTP response with \'%i %s\' from server` (503 Service Unavailable)

  See https://ci.appveyor.com/project/DrahtBot/bitcoin/build/master.2001. It shows "Rejecting request while shutting down" between "RPC stopped" and "Stopped HTTP server"

Tree-SHA512: e1f50ab9096cf23494ccc2850c01516c4a75f112c99108759157b22fce2011682a4b88216f206702f6a56e960182c00098053ad75f13aa0eafe27046adae63da

test/functional/test_framework/test_node.py

@@ -169,7 +169,9 @@ def wait_for_rpc_connection(self):
                 if e.errno != errno.ECONNREFUSED:  # Port not yet open?
                     raise  # unknown IO error
             except JSONRPCException as e:  # Initialization phase
-                if e.error['code'] != -28:  # RPC in warmup?
+                # -28 RPC in warmup
+                # -342 Service unavailable, RPC server started but is shutting down due to error
+                if e.error['code'] != -28 and e.error['code'] != -342:
                     raise  # unknown JSON RPC exception
             except ValueError as e:  # cookie file not found and no rpcuser or rpcassword. pivxd still starting
                 if "No RPC credentials" not in str(e):