after drop host, should delete the storage from `show hosts`

[HarrisChu]

(root@nebula) [(none)]> drop hosts 172.28.2.1:9779
Execution succeeded (time spent 2333/7137 us)

(root@nebula) [(none)]> show hosts
+--------------+------+-----------+--------------+----------------------+------------------------+
| Host         | Port | Status    | Leader count | Leader distribution  | Partition distribution |
+--------------+------+-----------+--------------+----------------------+------------------------+
| "172.28.2.1" | 9779 | "OFFLINE" | 0            | "No valid partition" | "No valid partition"   |
| "172.28.2.2" | 9779 | "ONLINE"  | 0            | "No valid partition" | "No valid partition"   |
| "172.28.2.3" | 9779 | "ONLINE"  | 0            | "No valid partition" | "No valid partition"   |
| "Total"      |      |           | 0            |                      |                        |
+--------------+------+-----------+--------------+----------------------+------------------------+
Got 4 rows (time spent 1314/5476 us)


(root@nebula) [(none)]> show zones
+--------------------------------+--------------+------+
| Name                           | Host         | Port |
+--------------------------------+--------------+------+
| "default_zone_172.28.2.2_9779" | "172.28.2.2" | 9779 |
| "default_zone_172.28.2.3_9779" | "172.28.2.3" | 9779 |
+--------------------------------+--------------+------+
Got 2 rows (time spent 1282/14776 us)

Wed, 29 Dec 2021 11:47:00 CST

excepted result:

1. do not display this host in show hosts.

[HarrisChu]

#3583