Improve performances when expanding all images and they were already loaded.

src/features.coffee

@@ -3272,6 +3272,7 @@ ImageExpand =
     return unless $.hasClass thumb, 'expanding' # contracted before the image loaded
     prev = post.nodes.root.getBoundingClientRect()
     post.file.isExpanded = true
+    $.queueTask ->
       $.addClass post.nodes.root, 'expanded-image'
       $.rmClass  post.file.thumb, 'expanding'
       return unless prev.top + prev.height <= 0