Fix check-merged so it checks the actual output file

git-svn-id: https://svn.apache.org/repos/asf/jakarta/bsf/trunk@798463 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/bsf3/bsf-engines/build.xml b/bsf3/bsf-engines/build.xml
index 1e165f5..00d78e0 100644
--- a/bsf3/bsf-engines/build.xml
+++ b/bsf3/bsf-engines/build.xml
@@ -27,7 +27,7 @@
     <target name="check-merged">
         <condition property="already.merged" >
            <and>
-              <available file="${basedir}/target/bsf-engines.jar"/>
+              <available file="${basedir}/target/bsf-engines-${bsf.version}.jar"/>
            </and>
         </condition>