Fix Maven site build

[slawekjaranowski]

In this PR I fixed Maven site build.

Still is failing IT test - forked-lifecycle on MacOs jdk 11 and 17 with exception:

Caused by: java.lang.NullPointerException
    at org.apache.commons.lang3.SystemUtils.isJavaVersionAtLeast (SystemUtils.java:1626)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.getJavadocExecutable (AbstractJavadocMojo.java:3589)
    at org.apache.maven.plugins.javadoc.AbstractJavadocMojo.executeReport (AbstractJavadocMojo.java:1963)
    at org.apache.maven.plugins.javadoc.JavadocReport.generate (JavadocReport.java:130)
    at org.apache.maven.plugins.site.render.ReportDocumentRenderer.renderDocument (ReportDocumentRenderer.java:239)
    at org.apache.maven.doxia.siterenderer.DefaultSiteRenderer.render (DefaultSiteRenderer.java:349)
    at org.apache.maven.plugins.site.render.SiteMojo.renderLocale (SiteMojo.java:198)
    at org.apache.maven.plugins.site.render.SiteMojo.execute (SiteMojo.java:147)

If your dependency updates #7, #8 will not resolve it, I will create issue for it and fix.

[cstamas]

There are still some issues in here?

[slawekjaranowski]

I didn't investigate so mach it - probably there is problem with some old dependencies or plugins used in IT tests.

As I wrote I will wait for your PR ... maybe it resolve it.
I want to merge it and wait for your changes.