EventHistory Overview: Show the load more link as button and centered

refs #8615

modules/monitoring/application/views/scripts/list/eventhistory.phtml

@@ -117,7 +117,7 @@ if (! $this->compact): ?>
     )
   ); ?>
  <?php else: ?>
-  <?= $this->qlink(
+  <div class="load-more-container"><?= $this->qlink(
     $this->translate('Load More'),
     $url->setAnchor('page-' . ($page + 1)),
     array(
@@ -125,9 +125,9 @@ if (! $this->compact): ?>
     ),
     array(
       'id'      => 'load-more',
-      'class'   => 'pull-right load-more'
+      'class'   => 'pull-right load-more button-like'
     )
-  ); ?>
+  ); ?></div>
  <?php endif ?>
 <?php endif ?>
 </div>

public/css/icinga/pagination.less

@@ -70,4 +70,10 @@ a.show-more, a.load-more {
 a.load-more-hint {
   display: inline-block;
   margin-left: 1em;
+}
+
+div.load-more-container {
+  display: table;
+  margin: 0 auto;
+  margin-top: 0.5em;
 }