#21 Patches to build on openjdk 15

[jonchang]

I'm in the process of migrating Homebrew to use openjdk 15. We have found that the attached patch is necessary to build htmlcleaner with this newer java version. It fixes the error:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.9:jar (attach-javadocs) on project htmlcleaner: Execution attach-javadocs of goal org.apache.maven.plugins:maven-javadoc-plugin:2.9:jar failed: An API incompatibility was encountered while executing org.apache.maven.plugins:maven-javadoc-plugin:2.9🫙 java.lang.ExceptionInInitializerError: null

https://github.com/Homebrew/homebrew-core/pull/62605

[Scott Wilson]

That's fantastic Jon - thanks for submitting the patch. I'll review it this week.

[Londie Lexingtuon PadillaPerez]