Fix warning "'reportOutputDirectory' is unknown for plugin 'maven-javadoc-plugin:3.11.1:jar (attach-javadocs)'" (#1776)

`reportOutputDirectory` parameter was removed in maven-javadoc-plugin
version 3.10.0 by
https://github.com/apache/maven-javadoc-plugin/commit/9638a6a76c6db53c3bf8ffbd5cec7318b0e25303
(https://issues.apache.org/jira/browse/MJAVADOC-785).

This was overlooked in commit 435579f27cb8259ba14c1a868245a843e053211f.

`outputDirectory` parameter can be used to restore prior behavior,
but this customization seems unnecessary.
1 file changed