Make sure build aborts if there's an error

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/integration/sharepoint-2010/trunk@1362047 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.xml b/build.xml
index 45249ce..017381c 100644
--- a/build.xml
+++ b/build.xml
@@ -46,7 +46,7 @@
 
     <target name="compile" depends="precompile-check" if="canBuild">
         <copy todir="webservice/Web References/SPPermissionsService" file="wsdls/Permissions.wsdl"/>
-        <exec executable="cmd" dir="webservice">
+        <exec executable="cmd" dir="webservice" failonerror="true" failifexecutionfails="true">
             <arg value="/c"/>
             <arg value="build.bat"/>
         </exec>