Tag list: added info when there are no tags

src/Views/tag-list.phtml

@@ -25,6 +25,9 @@
 	</ul>
 </nav>
 
+<?php if (empty($this->context->transport->tags)): ?>
+	<p class="alert alert-warning">No tags to show.</p>
+<?php else: ?>
 	<?php $max = max([0]+array_map(function($x) { return $x['post_count']; }, $this->context->transport->tags)); ?>
 	<?php $add = 0. ?>
 	<?php $mul = 10. / max(1, log(max(1, $max))) ?>
@@ -42,3 +45,4 @@
 			<?php endforeach ?>
 		</ul>
 	</div>
+<?php endif ?>