Fix typo.

Actually I dodn't mean to include this file with my last commit, but
now that it's in ...

This is part of my ongoing effort to run the .NET tests against a fink
installed mono-0.23 on my iBook (there no jit for PPC yet).


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@275223 13f79535-47bb-0310-9956-ffa450edef68

src/etc/testcases/taskdefs/optional/dotnet.xml

@@ -161,7 +161,7 @@
     </csc>
     <available property="app.created" file="${testCSC.exe}"/>
     <fail unless="app.created">No app ${testCSC.exe} created</fail>
-    <exec executable="${mono.execuatble}" failonerror="true">
+    <exec executable="${mono.executable}" failonerror="true">
       <arg value="${testCSC.exe}"/>
     </exec> 
     <delete file="${testCSC.exe}"/>