Fix adding images to new identity signatures

It already worked only on edits, because the image data for new identity
was stored in the wrong session item.

CHANGELOG

@@ -4,6 +4,7 @@ CHANGELOG Roundcube Webmail
 - Managesieve: Fix handling of scripts with nested rules (#5540)
 - Fix variable substitution in ldap host for some use-cases, e.g. new_user_identity (#5544)
 - Enigma: Fix PHP fatal error when decrypting a message with invalid signature (#5555)
+- Fix adding images to new identity signatures
 
 RELEASE 1.2.3
 -------------

program/steps/settings/save_identity.inc

@@ -96,7 +96,7 @@ if (!empty($save_data['signature']) && !empty($save_data['html_signature'])) {
     unset($_POST['_signature']);
 }
 
-// update an existing contact
+// update an existing identity
 if ($_POST['_iid']) {
     $iid = rcube_utils::get_input_value('_iid', rcube_utils::INPUT_POST);
 

program/steps/settings/upload.inc

@@ -25,7 +25,7 @@ if (!empty($_GET['_progress'])) {
 }
 
 $from = rcube_utils::get_input_value('_from', rcube_utils::INPUT_GET);
-$type = str_replace('edit-', '', $from);
+$type = preg_replace('/(add|edit)-/', '', $from);
 
 if ($RCMAIL->action == 'upload-display') {
     $id = 'undefined';