Fix regression where groups with email address were resolved to its members' addresses

CHANGELOG

@@ -2,6 +2,7 @@ CHANGELOG Roundcube Webmail
 ===========================
 
 - Fix bug where mail content frame couldn't be reset in some corner cases (#5608)
+- Fix regression where groups with email address were resolved to its members' addresses
 - Fix so group/addressbook selection is retained on page refresh
 - Fix bug where signature couldn't be added above the quote in Firefox 51 (#5628)
 

program/steps/mail/autocomplete.inc

@@ -104,6 +104,11 @@ if (!empty($book_types) && strlen($search)) {
                             $contact['display'] = $display;
                         }
 
+                        // groups with defined email address will not be expanded to its members' addresses
+                        if ($sql_arr['_type'] == 'group') {
+                            $contact['email'] = $email;
+                        }
+
                         $contacts[$index]  = $contact;
                         $sort_keys[$index] = sprintf('%s %03d', $contact['display'] ?: $name, $idx++);