Remove 2.2-specific collection xconf sample

Author: joewiz

src/main/xar-resources/data/lucene/listings/listing-3.xml

@@ -4,7 +4,7 @@
     xmlns:xlink="http://www.w3.org/1999/xlink">
     <info>
         <title>Full Text Index</title>
-        <date>1Q20</date>
+        <date>2Q21</date>
         <keywordset>
             <keyword>indexing</keyword>
         </keywordset>
@@ -49,11 +49,7 @@
             xlink:href="indexing#idxconf">documentation</link>. For example:</para>
 
         <example>
-            <title>collection.xconf for version 2.2</title>
-            <programlisting language="xml" xlink:href="listings/listing-3.xml"/>
-        </example>
-        <example>
-            <title>collection.xconf for version 3.0 and above.</title>
+            <title>collection.xconf (for version 3.0 and above).</title>
             <programlisting language="xml" xlink:href="listings/listing-4.xml"/>
         </example>