Resource Groups are not multi select in configuration

[archandha]

In the Resource Group selector there are all ResourceGroups listed that are accessible with the given credentials and within the selected SubscriptionID.

One can only select either one resourceGroup or but not only e.g. two of three.

While could be circumvented with setting up two importers or tweaking the access for the credentials, it would be more convenient to have a multi select which is indeed available in the Zend framework included and adapted by IcingaWeb2 - sadly, I didn't figure out how to use this in the configuration dialogue yet.