Patch for Drush to allow STDERR redirection for Drush in drush_backend_invoke_concurrent

drush_stderr_patch.diff

diff --git a/includes/backend.inc b/includes/backend.inc
index 4dce8365..89cec3cd 100644
--- a/includes/backend.inc
+++ b/includes/backend.inc
@@ -845,7 +845,7 @@ function drush_backend_invoke_concurrent($invocations, $common_options = array()
     $env_vars = $site_record['#env-vars'];
     $php = array_key_exists('php', $site_record) ? $site_record['php'] : (array_key_exists('php', $command_options) ? $command_options['php'] : NULL);
     $drush_command_path = drush_build_drush_command($drush_path, $php, $os, $is_remote, $env_vars);
-    $cmd = _drush_backend_generate_command($site_record, $drush_command_path . " " . _drush_backend_argument_string($drush_global_options, $os) . " " . $site_record_to_dispatch . " " . $command, $args, $commandline_options, $backend_options) . ' 2>&1';
+    $cmd = _drush_backend_generate_command($site_record, $drush_command_path . " " . _drush_backend_argument_string($drush_global_options, $os) . " " . $site_record_to_dispatch . " " . $command, $args, $commandline_options, $backend_options);
     $cmds[$site] = array(
       'cmd' => $cmd,
       'post-options' => $post_options,