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

CHANGELOG

@@ -14,6 +14,7 @@ CHANGELOG Roundcube Webmail
 - Fix bug where mail content frame couldn't be reset in some corner cases (#5608)
 - Fix bug where some classic skin images were not displayed in IE/Edge (#5614)
 - Fix bug where signature couldn't be added above the quote in Firefox 51 (#5628)
+- Fix regression where groups with email address were resolved to its members' addresses
 
 RELEASE 1.2.3
 -------------

program/steps/mail/autocomplete.inc

@@ -99,6 +99,11 @@ 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++);