Avoid devices image nonproportional resizing

Author: vsapronov

assets/css/old/styles.css

@@ -1778,7 +1778,7 @@ text-align: center;
 .device-img {
 	margin-left: auto !important;
     margin-right: auto !important;
-	height: 300px;
+	max-height: 300px;
 }
 
 /* Nextcloud Box page */