Bug-55895: typo in the manual

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1551525 13f79535-47bb-0310-9956-ffa450edef68

manual/Tasks/macrodef.html

@@ -70,7 +70,7 @@
       <tr>
         <td valign="top">backtrace</td>
         <td valign="top">
-          This controls the error traceback if they is an
+          This controls the error traceback if there is an
           error detected when running the macro. If this is
           set to true, there will be an error trackback, if false
           there will not be one. <em>Since Ant 1.7</em>.