Fix typo in CHANGES.txt: wrote HADOOP-8642 instead of HADOOP-8624.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1367347 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -88,7 +88,7 @@ Trunk (unreleased changes)
     HADOOP-8523. test-patch.sh doesn't validate patches before building
     (Jack Dintruff via jeagles)
 
-    HADOOP-8642. ProtobufRpcEngine should log all RPCs if TRACE logging is
+    HADOOP-8624. ProtobufRpcEngine should log all RPCs if TRACE logging is
     enabled (todd)
 
   BUG FIXES