Test gh-ost on master, the parameters have been added parameters output invalid

Example 1:

```shell
[shell ~]# gh-ost -user="root" -password="pwd4mysql" -host="172.16.3.88" -port=3306 -database="crm" -table="dish" -alter="drop colomn archer_test_column" –allow-on-master -switch-to-rbr –cut-over=default –default-retries=120 –throttle-control-replicas="172.16.3.95" –max-lag-millis=1500 –verbose -debug -execute
2017-09-07 17:32:20 FATAL You must be using ROW binlog format. I can switch it for you, provided --switch-to-rbr and that 172.16.3.88:3306 doesn't have replicas
```

Just in the example above, I have added the -switch-to-rbr parameter, and I also have from the replicas, do not know gh-ost is what principle to use to check from the replicas?

```
mysql> show slave hosts;
+-----------+------+------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID |
+-----------+------+------+-----------+--------------------------------------+
| 943308 | | 3306 | 999999 | 2fa13881-5a1e-11e7-a3d5-000c2902e7e6 |
| 99993306 | | 3306 | 999999 | 64dbbdec-5a1f-11e7-a3dd-000c29cb5c36 |
+-----------+------+------+-----------+--------------------------------------+
2 rows in set (0.00 sec)
```
Example 2：

```shell
[shell ~]# gh-ost –allow-on-master –max-load=Threads_running=25 –critical-load=Threads_running=1000 –chunk-size=1000 –throttle-control-replicas="172.16.3.95:3306" –max-lag-millis=1500 -user="root" -password="pwd4mysql" -host="172.16.3.88" -database="crm" -table="dish" –verbose -alter="drop colomn archer_test_column" –cut-over=default –default-retries=120 –switch-to-rbr –panic-flag-file=/tmp/ghost.panic.flag –postpone-cut-over-flag-file=/tmp/ghost.postpone.flag –execute
2017-09-07 17:41:31 FATAL --database must be provided and database name must not be empty
```
I have added the -database parameters, why suggested that my database parameters empty?
The first test gh-ost, do not know if the method is not used? I hope everyone and the author to help.