correct file size and add note about impending breakage of image_optim

Gemfile

@@ -63,7 +63,8 @@ gem 'email_reply_parser'
 
 # note: for image_optim to correctly work you need to follow
 # https://github.com/toy/image_optim
-gem 'image_optim'
+# pinned due to https://github.com/toy/image_optim/pull/75, docker image must be upgraded to upgrade
+gem 'image_optim', '0.20.2'
 gem 'multi_json'
 gem 'mustache'
 gem 'nokogiri'

Gemfile.lock

@@ -422,7 +422,7 @@ DEPENDENCIES
   highline
   hiredis
   htmlentities
-  image_optim
+  image_optim (= 0.20.2)
   librarian (>= 0.0.25)
   listen (= 0.7.3)
   logster
@@ -488,3 +488,6 @@ DEPENDENCIES
   uglifier
   unf
   unicorn
+
+BUNDLED WITH
+   1.10.6

app/models/upload.rb

@@ -100,6 +100,10 @@ class Upload < ActiveRecord::Base
 
         # optimize image
         ImageOptim.new.optimize_image!(file.path) rescue nil
+
+        # correct size so it displays the optimized image size which is the only
+        # one that is stored
+        filesize = File.size(file.path)
       end
 
       # compute the sha of the file