Enlarge the .item.date to contain larger date

I know it's not the best solution, a dynamic width would be the best but there
are some CSS constraints. I don't want to spend my time on this problem ;)

Fix https://github.com/FreshRSS/FreshRSS/issues/756

p/themes/base-theme/template.css

@@ -485,7 +485,7 @@ a.btn {
 	text-decoration: none;
 }
 .flux .item.date {
-	width: 145px;
+	width: 155px;
 	text-align: right;
 	overflow: hidden;
 }