Compatible with rails 5.1+

# in rails 5.1+
```
plugins/redmine_knowledgebase/init.rb:9:in `<top (required)>': undefined method `to_prepare' for ActionDispatch::Reloader:Class (NoMethodError)
Did you mean?  to_param
```
# solution
```
init.rb   (line 9)

`ActionDispatch::Reloader.to_prepare` Instead of  `ActiveSupport::Reloader.to_prepare`
```