Fix build problem with Java 11+

diff --git a/pom.xml b/pom.xml
index 8f56047..0104204 100644
--- a/pom.xml
+++ b/pom.xml
@@ -195,6 +195,10 @@
           </excludes>
         </configuration>
       </plugin>
+      <plugin>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.1.1</version>
+      </plugin>
     </plugins>
   </build>
 
diff --git a/src/main/java/org/apache/maven/dist/tools/masterjobs/ListMasterJobsMojo.java b/src/main/java/org/apache/maven/dist/tools/masterjobs/ListMasterJobsMojo.java
index a280b98..337ffa7 100644
--- a/src/main/java/org/apache/maven/dist/tools/masterjobs/ListMasterJobsMojo.java
+++ b/src/main/java/org/apache/maven/dist/tools/masterjobs/ListMasterJobsMojo.java
@@ -197,7 +197,7 @@
      * <a href="https://gitbox.apache.org/repos/asf">Gitbox main page</a>.
      *
      * @return the list of repository names (without ".git")
-     * @throws IOException
+     * @throws IOException problem with reading repository index
      */
     protected Collection<String> repositoryNames()
         throws IOException