[#5228] Missing auto links following a 1.5.3 to 1.5.4 upgrade

https://github.com/EnMasseProject/enmasse/issues/5228

If a user updates from 1.5.3.GA to 1.5.4.GA and has an existing standard address space with queue type address defined, those address with become unready and report that their auto links are missing.

Examining the broker log will show that the connectors have failed like this:

{{2021-01-05T11:15:53.090Z INFO [server] AMQ221022: unable to start connector service: $override-router-connector-out: java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:592)
at java.lang.Integer.parseInt(Integer.java:615)
at java.util.Optional.map(Optional.java:215)
at org.apache.activemq.artemis.integration.amqp.AMQPConnectorServiceFactory.createConnectorService(AMQPConnectorServiceFactory.java:135)
at org.apache.activemq.artemis.core.server.impl.ConnectorsService.createService(ConnectorsService.java:105)
at org.apache.activemq.artemis.core.server.impl.ConnectorsService.start(ConnectorsService.java:80)
at org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl.internalStart(ActiveMQServerImpl.java:637)
at org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl.start(ActiveMQServerImpl.java:526)
at org.apache.activemq.artemis.integration.FileBroker.start(FileBroker.java:70)
at org.apache.activemq.artemis.cli.commands.Run.execute(Run.java:84)
at org.apache.activemq.artemis.cli.Artemis.internalExecute(Artemis.java:153)
at org.apache.activemq.artemis.cli.Artemis.execute(Artemis.java:101)
at org.apache.activemq.artemis.cli.Artemis.execute(Artemis.java:128)}}