Removing javadoc parallel build (not needed)

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>

Jenkinsfile

@@ -48,18 +48,6 @@ pipeline {
             }
           }
         }
-
-        stage("Build Javadoc") {
-          agent { node { label 'linux' } }
-          steps {
-            container( 'jetty-build' ) {
-              timeout( time: 40, unit: 'MINUTES' ) {
-                mavenBuild( "jdk11",
-                            "install javadoc:javadoc -DskipTests -Dpmd.skip=true -Dcheckstyle.skip=true", "maven3", false)
-              }
-            }
-          }
-        }
       }
     }
   }