Replace dead link in maven-javadoc-plugin

The link to https://javaee-spec.java.net/nonav/javadocs/ is long dead
since 2017. For some reason this causes excruciatingly long wait times until
connection attempts eventually timeout. Regardless of that it's worth updating.
This change replaces it with link to another publicly available
legacy documentation at https://javaee.github.io/javaee-spec/javadocs/

Author: Bouncheck

pom.xml

@@ -527,7 +527,7 @@
                             <link>http://www.joda.org/joda-time/apidocs/</link>
                             <link>http://fasterxml.github.io/jackson-core/javadoc/2.8/</link>
                             <link>http://fasterxml.github.io/jackson-databind/javadoc/2.7/</link>
-                            <link>https://javaee-spec.java.net/nonav/javadocs/</link>
+                            <link>https://javaee.github.io/javaee-spec/javadocs/</link>
                         </links>
                         <!-- optional dependencies from other modules (must be explicitly declared here in order to be correctly resolved) -->
                         <additionalDependencies>