[ticket/11935] Remove obsolete table attributes from Prosilver

cellpadding, cellspacing, border are obsolete table attributes.
They are handled by CSS already using table and .table1

PHPBB3-11935

phpBB/styles/prosilver/template/ucp_notifications.html

@@ -9,7 +9,7 @@
 		<p>{TITLE_EXPLAIN}</p>
 
 		<!-- IF MODE == 'notification_options' -->
-			<table class="table1" cellspacing="1">
+			<table class="table1">
 				<thead>
 					<th>{L_NOTIFICATION_TYPE}</th>
 					<!-- BEGIN notification_methods -->