Remove duplicate attribute

Obtained from:Yuji Yamano


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@275782 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/copy.html

@@ -118,13 +118,6 @@ operation as <a href="../CoreTypes/filterset.html">filtersets</a>
     <td align="center">No - defaults to the value of the encoding
     attribute if given or the default JVM encoding otherwise.</td>
   </tr>
-  <tr>
-    <td valign="top">outputencoding</td>
-    <td valign="top">The encoding to use when writing the files.
-    <em>since Ant 1.6</em>.</td>
-    <td align="center">No - defaults to the value of the encoding
-    attribute if given or the default JVM encoding otherwise.</td>
-  </tr>
   <tr>
     <td valign="top">enablemultiplemapping</td>
     <td valign="top">