Fix security issue in contact photo handling (#1490379)

CHANGELOG

@@ -16,6 +16,7 @@ CHANGELOG Roundcube Webmail
 - Fix mouseup event handling when dragging a list record (#1490359)
 - Fix bug where preview_pane setting wasn't always saved into user preferences (#1490362)
 - Fix bug where messages count was not updated after message move/delete with skip_deleted=false (#1490372)
+- Fix security issue in contact photo handling (#1490379)
 
 RELEASE 1.1.1
 -------------

program/steps/addressbook/photo.inc

@@ -80,11 +80,6 @@ if (strlen($data) < 1024 && filter_var($data, FILTER_VALIDATE_URL)) {
     $RCMAIL->output->redirect($data);
 }
 
-// deliver alt image
-if (!$data && ($alt_img = rcube_utils::get_input_value('_alt', rcube_utils::INPUT_GPC)) && is_file($alt_img)) {
-    $data = file_get_contents($alt_img);
-}
-
 // cache for one day if requested by email
 if (!$cid && $email) {
     $RCMAIL->output->future_expire_header(86400);