Merge pull request apache#214 from Vampire/fix-docs

Fix copy&paste error in signjar documentation

Author: bodewig

manual/Tasks/signjar.html

@@ -232,7 +232,7 @@ <h3>Parameters as nested elements</h3>
   </tr>
   <tr>
     <td>arg</td>
-    <td>Use this to specify a <kbd>keytool</kbd>
+    <td>Use this to specify a <kbd>jarsigner</kbd>
     <a href="../using.html#arg">command line argument</a> not
     explicitly supported via an attribute.
     <em>since Ant 1.10.6</em>.</td>