re-enable DataHelperTest since the jenkins test was a success

core/java/build.xml

@@ -231,7 +231,9 @@
                     <exclude name="**/ElGamalAESEngineTest.java" />
                     <exclude name="**/StructureTest.java" />
                     <!-- DataHelperTest is *very* slow with cobertura -->
+                    <!--
                     <exclude name="**/DataHelperTest.java" />
+                    -->
                 </fileset>
             </batchtest>
             <formatter type="xml"/>