Fix mvn javadoc:javadoc failure, update javadoc plugin to 3.4.1

Issue-ID: AAI-3527

Signed-off-by: Fiete Ostkamp <Fiete.Ostkamp@telekom.de>
Change-Id: Ie69792925722607ea33e376f01a3d682bc0bd43b
diff --git a/pom.xml b/pom.xml
index 8f2ef42..21d3990 100644
--- a/pom.xml
+++ b/pom.xml
@@ -172,7 +172,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>2.10.4</version>
+                <version>3.4.1</version>
                 <configuration>
                     <failOnError>false</failOnError>
                     <doclet>org.umlgraph.doclet.UmlGraphDoc</doclet>