[Java][Spring] Add stopWait to pom.xml

[wing328]

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Description of the PR

This PR should fix the following:

[ERROR] Failed to execute goal org.eclipse.jetty:jetty-maven-plugin:9.2.15.v20160210:start (start-jetty) on project spring-mvc-j8-localdatetime: Failure: ShutdownMonitorThread already started -> [Help 1]

Ref:

• https://bugs.eclipse.org/bugs/show_bug.cgi?id=412637
• https://stackoverflow.com/questions/37419969/embedded-jetty-with-maven-example-fails-to-restart-address-already-in-use