Fix typo in tar documentation.

PR: 2120
Submitted by:	rxh@gers.com (Rey Hernandez)


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269147 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/tar.html

@@ -125,8 +125,8 @@ attributes
     <td align="center" valign="top">No</td>
   </tr>
   <tr>
-    <td valign="top">groupname</td>
-    <td valign="top">The username for the tar entry. This is not the same as the GID, which is 
+    <td valign="top">group</td>
+    <td valign="top">The groupname for the tar entry. This is not the same as the GID, which is 
                      not currently set by the tar task.</td>
     <td align="center" valign="top">No</td>
   </tr>