Fix best-effort flag name in dgraph increment tool.

"bo" did not create a best-effort query.

dgraph/cmd/counter/increment.go

@@ -49,6 +49,7 @@ func init() {
 	flag.String("addr", "localhost:9080", "Address of Dgraph alpha.")
 	flag.Int("num", 1, "How many times to run.")
 	flag.Bool("ro", false, "Only read the counter value, don't update it.")
+	flag.Bool("be", false, "Read counter value without retrieving timestamp from Zero.")
 	flag.Duration("wait", 0*time.Second, "How long to wait.")
 	flag.String("pred", "counter.val", "Predicate to use for storing the counter.")
 }