Merge pull request #753 from pcg79/master

Removes the redundant term "file size"

lib/paperclip.rb

@@ -373,7 +373,7 @@ module Paperclip
       min     = options[:greater_than] || (options[:in] && options[:in].first) || 0
       max     = options[:less_than]    || (options[:in] && options[:in].last)  || (1.0/0)
       range   = (min..max)
-      message = options[:message] || "file size must be between :min and :max bytes"
+      message = options[:message] || "must be between :min and :max bytes"
       message = message.call if message.respond_to?(:call)
       message = message.gsub(/:min/, min.to_s).gsub(/:max/, max.to_s)