HA3 的main-stable-0.4分支主README.md 查询语法有点问题

main-stable-0.4分支的/README.md中的Query Demo Index部分使用示例有问题。

范例给的如下行所示，请求会报sql请求解析错误。
python curl_http.py 45800 "query=select count(*) from in0"

看代码后发现必须加上 databaseName参数，否则请求会被自动过滤。示例如下：
python curl_http.py 45800 "query=select count(*) from in0&&kvpair=databaseName:in0"

1.0版本后面没这个问题，自动加上了databaseName参数。

Open /README.md on the main-stable-0.4 branch and locate the Query Demo Index section. Compare the example with curl_http.py usage, update it to include the databaseName parameter, and verify that the documented query no longer produces the reported SQL parsing error.

Written by the indexing model from the issue text.