remove assertion of something we're not actually testing here

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@537873 13f79535-47bb-0310-9956-ffa450edef68

src/tests/antunit/taskdefs/condition/resourcecontains-test.xml

@@ -13,7 +13,6 @@
   </target>
 
   <target name="testcontains">
-    <au:assertFileExists file="${file}"/>
     <au:assertTrue message="Should have found the text in the resource">
       <resourcecontains resource="${file}" substring="text"/>
     </au:assertTrue>