0d663f8 Fixes issue #12067 `sendmany` curl example is wrong. (251)
Pull request description:
The example curl command in the `sendmany` RPC help results in an error:
```
{"result":null,"error":{"code":-1,"message":"JSON value is not an object as expected"},"id":"curltest"}
```
because - as reported in #12067 - the second element in the `params` array should be a JSON object.
This PR removes the escaped backslash and quote characters that serialize the JSON object to a string and make it a plain JSON object:
```
curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "sendmany", "params": ["", {"1D1ZrZNe3JUo7ZycKEYQQiQAWd9y54F4XX":0.01,"1353tsE8YMTA4EuV7dgUXGjNFf9KpVvKHz":0.02}, 6, "testing"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/
```
which (when executed with valid addresses) yields the expected result:
```
{"result":"c446213f06ee4489660ed5dc47d65daca27345d0b5fc5bd344ebca78b2d87356","error":null,"id":"curltest"}
```
---
Backport of Core PR12077