Fix Capture Debug page timeout (#10926)

Override symfony 60s execution timeout. Allows the capture page to output discovery and poller process results, if the process lasts longer than 60s.

Similar fix to commit https://github.com/murrant/librenms/commit/561e2fb6e26bc272550dd52684f0733afa0673e9

includes/html/output/capture.inc.php

@@ -54,6 +54,8 @@ switch ($type) {
 
 // ---- Output ----
 $proc = new \Symfony\Component\Process\Process($cmd);
+$proc->setTimeout(Config::get('snmp.exec_timeout', 1200));
+
 if ($_GET['format'] == 'text') {
     header("Content-type: text/plain");
     header('X-Accel-Buffering: no');