mdsal/docs build fails under Java 11 due to JavaDoc error

[INFO] --- maven-javadoc-plugin:3.0.0:jar (attach-javadocs) @ mdsal-docs ---
[ERROR] Error fetching link: /home/vorburger/dev/ODL/git/mdsal/binding/mdsal-binding-test-utils/target/apidocs/package-list. Ignored it.
[INFO] 
1 error
100 warnings

...

[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:3.0.0:jar (attach-javadocs) on project mdsal-docs: MavenReportException: Error while generating Javadoc: 
[ERROR] Exit code: 1 - javadoc: warning - You have specified the HTML version as HTML 4.01 by using the -html4 option.
[ERROR] The default is currently HTML5 and the support for HTML 4.01 will be removed
[ERROR] in a future release. To suppress this warning, please ensure that any HTML constructs
[ERROR] in your comments are valid in HTML5, and remove the -html4 option.
[ERROR] javadoc: error - Error fetching URL: https://static.javadoc.io/junit/junit/4.11/
[ERROR] /home/vorburger/dev/ODL/git/mdsal/docs/target/src/org/opendaylight/yangtools/yang/binding/InstanceIdentifier.java:35: warning: empty <p> tag
[ERROR]  * <p>
[ERROR]    ^
[ERROR] /home/vorburger/dev/ODL/git/mdsal/docs/target/src/org/opendaylight/mdsal/binding/api/ActionProviderService.java:45: warning: no @param for <O>
[ERROR]         ObjectRegistration<S> registerImplementation(Class<T> actionInterface, S implementation,
...