Wrong start class for config client

[svennela]

https://github.com/mstine/CloudNativeArchitectureClass/tree/master/day_02/session_05/lab_14/complete/springbox-config-client

    <start-class>io.springbox.configserver.SpringboxConfigServerApplication</start-class>

should be

        <start-class>io.springbox.configclient.SpringboxConfigClientApplication</start-class>