Fixing javadoc with Java 11

git-svn-id: https://svn.apache.org/repos/asf/santuario/xml-security-java/trunk@1869655 13f79535-47bb-0310-9956-ffa450edef68

pom.xml

diff --git a/pom.xml b/pom.xml
index 584f8a6..dd52034 100644
--- a/pom.xml
+++ b/pom.xml
@@ -301,7 +301,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>3.0.1</version>
+                <version>3.1.0</version>
             </plugin>
 
         </plugins>
@@ -311,7 +311,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-javadoc-plugin</artifactId>
-                    <version>3.0.1</version>
+                    <version>3.1.0</version>
                     <executions>
                         <execution>
                             <goals>
@@ -320,6 +320,7 @@
                         </execution>
                     </executions>
                     <configuration>
+                        <source>8</source>
                         <attach>true</attach>
                         <excludePackageNames>org.apache.xml.security.binding.*</excludePackageNames>
                     </configuration>