Role access plugin removes its own option in summary_title method

A very specific issue - but I'm writing a module that allows multiple views access plugins to work on the same view - combining them with a logical operator. In the UI for a view the user can choose multiple access plugins and set their options in one form.

To help the UI I call each access plugins' summary_title() method before calling their options_form() method. Now, it appears that the role access plugin calls array_unshift($this->options['role']) during it's summary_title() method to grab the role selected. However this inadvertently wipes out that option for the rest of the lifetime of that instance of the plugin.

While I realise that it has never caused a problem before - essentially a call to an access plugin's summary_title() method has never been followed by a call to any other method on the plugin, it is causing a problem for my module. And the solution is so simple.

I've fixed the issue in all branches - I'll add a patch here shortly.