Fix the bug of "if" in validates_presence_of :collapse_key

[kaosf]

:time_to_live? is always evaluated as true, so validates_presence_of :collapse_key is always enabled in spite of whether time_to_live is nil or not.

You might fix it from if to , if:.

References;

• http://apidock.com/rails/ActiveRecord/Validations/ClassMethods/validates_presence_of
• http://stackoverflow.com/questions/10501401/validates-presence-of-if-condition-on-rails-3-2-and-mongoid-simple-form