Mailings from search results as ACL user without unsubscribe group

Steps to reproduce:
1. Create a ACL restricted user
2. Create a mailing from a search results

Since the restricted user has no acl permission for the hidden smart group it is not detected as mandory group by ang/crmMailing/Recipient.js. 'Search Results' is not shown as the receipient group, but the recipient count is still correct.

The check to enable and force the selection of an unsubscribe group fails in ang/crmMailing/EditUnsubGroupCtrl.js.

The mailing will still be send regardless!

Implications:

• user cannot continue the mailing later (technically its possible by knowing the url, but that's a different issue)
• user cannot view the mailing report
• unsubscribing mail recipient gets removed from every added group and gets a removed entry for every dynamic group
• resubscribing fails with a sql syntax error, since there is no group to resubscribe to be found