Update flag help

Signed-off-by: Matt Lord <mattalord@gmail.com>

go/flags/endtoend/vttablet.txt

@@ -412,6 +412,7 @@ Flags:
       --vreplication_copy_phase_duration duration                        Duration for each copy phase loop (before running the next catchup: default 1h) (default 1h0m0s)
       --vreplication_copy_phase_max_innodb_history_list_length int       The maximum InnoDB transaction history that can exist on a vstreamer (source) before starting another round of copying rows. This helps to limit the impact on the source tablet. (default 1000000)
       --vreplication_copy_phase_max_mysql_replication_lag int            The maximum MySQL replication lag (in seconds) that can exist on a vstreamer (source) before starting another round of copying rows. This helps to limit the impact on the source tablet. (default 43200)
+      --vreplication_enable_http_log                                     Enable the /debug/vrlog HTTP endpoint, which will produce a log of the queries executed on primary tablets in the target keyspace by all VReplication workflows that are in the running/replicating phase.
       --vreplication_experimental_flags int                              (Bitmask) of experimental features in vreplication to enable (default 7)
       --vreplication_heartbeat_update_interval int                       Frequency (in seconds, default 1, max 60) at which the time_updated column of a vreplication stream when idling (default 1)
       --vreplication_max_time_to_retry_on_error duration                 stop automatically retrying when we've had consecutive failures with the same error for this long after the first occurrence

go/vt/vttablet/common/flags.go

@@ -100,5 +100,5 @@ func registerFlags(fs *pflag.FlagSet) {
 
 	fs.Uint64Var(&mysql.ZstdInMemoryDecompressorMaxSize, "binlog-in-memory-decompressor-max-size", mysql.ZstdInMemoryDecompressorMaxSize, "This value sets the uncompressed transaction payload size at which we switch from in-memory buffer based decompression to the slower streaming mode.")
 
-	fs.BoolVar(&vreplicationEnableHttpLog, "vreplication_enable_http_log", vreplicationEnableHttpLog, "Enable the /debug/vrlog HTTP endpoint, which will produce a log of the queries executed on the target keyspace primary tablets for all workflows.")
+	fs.BoolVar(&vreplicationEnableHttpLog, "vreplication_enable_http_log", vreplicationEnableHttpLog, "Enable the /debug/vrlog HTTP endpoint, which will produce a log of the queries executed on primary tablets in the target keyspace by all VReplication workflows that are in the running/replicating phase.")
 }