Merge branch '5748-nightly-db-user-will-not-assigned-with-database-db-users-are-not-created-in-mariadb' into 'develop'

Resolve "[Nightly] DB User will not assigned with Database / DB Users are not created in MariaDB"

Closes #5748

See merge request ispconfig/ispconfig3!1186

Author: Till Brehm

server/plugins-available/mysql_clientdb_plugin.inc.php

@@ -137,7 +137,7 @@ function process_host_list($action, $database_name, $database_user, $database_pa
 			if($user_access_mode == 'r') $grants = 'SELECT';
 			elseif($user_access_mode == 'rd') $grants = 'SELECT, DELETE, ALTER, DROP';
 
-			$database_name = str_replace('_', '\\_', $link->escape_string($database_name));
+			$database_name = $link->escape_string($database_name);
 
 			if($action == 'GRANT') {
 				if($user_access_mode == 'r' || $user_access_mode == 'rd') {