Merge branch '6845-replace_remove_is_redhat_os' into 'develop'

Switch to get_os_type and ditch is_redhat_os in nginx_plugin

Closes #6845

See merge request ispconfig/ispconfig3!2001

Author: Till Brehm

server/lib/classes/system.inc.php

@@ -2357,16 +2357,6 @@ public function is_allowed_group($groupname, $check_id = true, $restrict_names =
 		return true;
 	}
 
-	public function is_redhat_os() {
-		global $app;
-
-		if(file_exists('/etc/redhat-release') && (filesize('/etc/redhat-release') > 0)) {
-			return true;
-		} else {
-			return false;
-		}
-	}
-
 	public function get_os_type() {
 		global $app;
 

server/plugins-available/nginx_plugin.inc.php

@@ -2941,7 +2941,8 @@ private function php_fpm_pool_update ($data, $web_config, $pool_dir, $pool_name,
 		$tpl->setVar('fpm_user', $data['new']['system_user']);
 
 		// RH workaround here
-		if($app->system->is_redhat_os() == true) {
+		$dist = $app->system->get_os_type();
+		if(isset($dist['type']) && $dist['type'] == 'redhat'){
 			$tpl->setVar('fpm_group', $data['new']['system_group']);
 			$tpl->setVar('fpm_listen_group', $data['new']['system_group']);
 		} else {