change thumb image to mobile size

app/controllers/spaces_controller.rb

@@ -118,7 +118,7 @@ class SpacesController < ApplicationController
     images = []
     unit.floor_sub_unit_images.each do |image|
       images << {
-        "image-thumb-url" => image.image.thumb.url,
+        "image-thumb-url" => image.image.mobile.url,
         "image-url" => image.image.url,
         "alt-image" => unit.title
       }