RPC am_set_info.php does not return success correctly

[drshawnkwang]

Describe the bug
There is an extra success() function being called by am_set_info.php, line 239

Steps To Reproduce

1. Send a Web RPC command to am_set_info.php such as https://PROJECT_URL/am_set_info.php?account_key=abc&show_hosts=0

Expected behavior
The code should return:

<am_set_info_reply>
<success/>
</am_set_info_reply>

System Information (please complete the following information):

• BOINC Server Version: since 2018

Additional context
I believe the correct solution is to remove the success() function on line 239. There is success call at the bottom (L270) that should be called instead. If there are errors, there are xml_error() function calls.

The E@H Drupal web code breaks because of this bug. And should be fixed in upstream Web code. I'll create a PR for this soon.