MAPREDUCE-7463. Fix missing comma in HistoryServerRest.html response body (#6342). Contributed by wangzhongwei.

Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/site/markdown/HistoryServerRest.md

@@ -176,7 +176,7 @@ Response Body:
                 "finishTime" : 1326381356010
              },
              {
-                "submitTime" : 1326381446500
+                "submitTime" : 1326381446500,
                 "state" : "SUCCEEDED",
                 "user" : "user1",
                 "reducesTotal" : 1,