* change deprecated HTML <center> tag to <div style="text-align:center">

system/templates/success.html.twig

@@ -30,7 +30,7 @@
 {% if custom_buttons is defined %}
 {{ custom_buttons|raw }}
 {% else %}
-<center>
+<div style="text-align:center">
 	<table border="0" cellspacing="0" cellpadding="0">
 		<form action="{{ getLink('account/manage') }}" method="post">
 			<tr>
@@ -40,5 +40,5 @@
 			</tr>
 		</form>
 	</table>
-</center>
+</div>
 {% endif %}