Revert disable Javadoc generation on 11+

pom.xml

@@ -164,18 +164,6 @@
     </modules>
 
     <profiles>
-        <profile>
-            <!-- Disable Javadoc generation on Java 11, as it fails with message on 11.0.2:
-                 "error - The code being documented uses modules but the packages defined in https://docs.oracle.com/javase/7/docs/api/ are in the unnamed module."
-                 -->
-            <id>jdk11-build</id>
-            <activation>
-                <jdk>[11, 12)</jdk>
-            </activation>
-            <properties>
-                <javadoc.disabled>true</javadoc.disabled>
-            </properties>
-        </profile>
         <profile>
             <id>travis</id>
             <activation>