Fix javadoc generation ?

pom.xml

@@ -192,7 +192,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>2.9.1</version>
+                <version>3.1.1</version>
                 <executions>
                     <execution>
                         <phase>package</phase>
@@ -201,9 +201,8 @@
                             <goal>jar</goal>
                         </goals>
                         <configuration>
-                            <additionalparam>${javadoc.opts}</additionalparam>
-                            <source>8</source>
                             <doclint>none</doclint>
+                            <source>8</source>
                         </configuration>
                     </execution>
                 </executions>