update JUNG javadoc link

the new link seems to reference the 2.1 version (used by us) instead of 2.0 and the github runners often get blocked by the host of the old documentation.

Author: mtf90

pom.xml

@@ -247,7 +247,7 @@ limitations under the License.
         <brics-automaton.apidocs>https://www.brics.dk/automaton/doc</brics-automaton.apidocs>
         <checkerframework.apidocs>https://checkerframework.org/releases/${checkerframework.version}/api/</checkerframework.apidocs>
         <java8.apidocs>https://docs.oracle.com/javase/8/docs/api/</java8.apidocs>
-        <jung.apidocs>https://jung.sourceforge.net/doc/api/</jung.apidocs>
+        <jung.apidocs>https://jrtom.github.io/jung/javadoc/</jung.apidocs>
     </properties>
 
     <!--