Submission RPC fails due to a change with the display_errors setting.

[lfield]

Describe the bug

The RPC command cmd=batch_files from get_output.php fails with the 1.4.7 release.
The client receives the error "zipfile.BadZipFile: File is not a zip file" due to the file containing a HTML response. e.g.

<br />
<b>Warning</b>:  filesize(): stat failed for /boincdata/boinc/project/lhcathome/html/cache/boinc_batch_gzCHsF.zip in <b>/boincdata/boinc/project/lhcathome/html/inc/util.inc</b> on line <b>1092</b><br />
<br />
<b>Warning</b>:  readfile(/boincdata/boinc/project/lhcathome/html/cache/boinc_batch_gzCHsF.zip): Failed to open stream: No such file or directory in <b>/boincdata/boinc/project/lhcathome/html/inc/util.inc</b> on line <b>1094</b><br />
<br />
<b>Warning</b>:  unlink(/boincdata/boinc/project/lhcathome/html/cache/boinc_batch_gzCHsF.zip): No such file or directory in <b>/boincdata/boinc/project/lhcathome/html/user/get_output.php</b> on line <b>118</b><br />

This issue seems to be caused by the setting ini_set('display_errors', true); in util.inc

Steps to reproduce

No response

Expected behavior

No response

Screenshots

No response

System information

No response

Additional context

No response

[davidpanderson]

util.inc doesn't currently call ini_set('display_errors', true);

for job-submission stuff it's generally better to see the errors, so they can be fixed