Browser Back Button will duplicate Multiselection Fields

[OliverMannhart]

To reproduc just create following example app:

rails new test_app

add rails admin to gem file and run installer

rails g model Team name:string
rails g model Player team:references
rails db:migrate

add "has_many :players" to the model Team

start the rails app

After the rails app is created and running, do following:

go to http://localhost:3000/admin/
got to Teams
got to Add New (don't save anything)
leave fields empty, just click on Export or List

Use the browser back-button. You will get back to the Teams-Detail-View. But now the Players Selection is duplicated.
You can repeat this (browser forward, browser back) and it will keep adding new Player Selections. After a page refresh, they are gone.
Looks like there is a problem with the javascript which builds the selection.

Hope this helps to fix the issue.

But otherwise great gem!