Uppercased get params cause crash on index pages

In the current stable (v0.6.3) a query param starting with an uppercased letter causes a SyntaxError in index pages.

This is the reason: amatsuda/kaminari#568

In master branch this does not happen because of [this change](https://github.com/gregbell/active_admin/commit/dcbfd6653e6e8e053e70f83dae0a5625b86a77e0#diff-a388362633460ba06e0a1f38bbb8ce1aL81)

In any case why are you passing query params to paginate helper? Why don't you simply call

```ruby
options = {}
options[:param_name] = @param_name if @param_name
# Are query params or path params needed here?
text_node paginate(collection, options.symbolize_keys)
```

Could you fix this on 0-6-stable branch?