Merge branch '6521_database_list_sort_on_dbuser_column_admin' into 'develop'

Fix sorting of the database list by user, #6521

See merge request ispconfig/ispconfig3!1773

Author: Till Brehm

interface/web/sites/templates/database_admin_list.htm

@@ -23,7 +23,7 @@ <h1><tmpl_var name="list_head_txt"></h1>
                         <th data-column="sys_groupid"><tmpl_var name="sys_groupid_txt"></th>
                         <th data-column="server_id"><tmpl_var name="server_id_txt"></th>
 						<th data-column="parent_domain_id"><tmpl_var name="parent_domain_id_txt"></th>
-                        <th data-column="database_user"><tmpl_var name="database_user_txt"></th>
+                        <th data-column="database_user_id"><tmpl_var name="database_user_txt"></th>
                         <th data-column="database_name"><tmpl_var name="database_name_txt"></th>
                         <th class="small-col text-right">{tmpl_var name='search_limit'}</th>
                     </tr>