MINOR: Fix typo in 3.2.0 upgrade notes (apache#14851)

Reviewers: Josep Prat <[email protected]>

docs/upgrade.html

@@ -434,7 +434,7 @@ <h5><a id="upgrade_320_notable" href="#upgrade_320_notable">Notable changes in 3
             <a href="https://www.slf4j.org/codes.html#no_tlm">possible compatibility issues originating from the logging framework</a>.</li>
         <li>The example connectors, <code>FileStreamSourceConnector</code> and <code>FileStreamSinkConnector</code>, have been
             removed from the default classpath. To use them in Kafka Connect standalone or distributed mode they need to be
-            explicitly added, for example <code>CLASSPATH=./lib/connect-file-3.2.0.jar ./bin/connect-distributed.sh</code>.</li>
+            explicitly added, for example <code>CLASSPATH=./libs/connect-file-3.2.0.jar ./bin/connect-distributed.sh</code>.</li>
     </ul>
 
 <h4><a id="upgrade_3_1_0" href="#upgrade_3_1_0">Upgrading to 3.1.0 from any version 0.8.x through 3.0.x</a></h4>