Added correct update from old versions

db/upgrade.php

@@ -0,0 +1,52 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Keeps track of upgrades to the 'local_webhooks' plugin.
+ *
+ * @package   local_webhooks
+ * @copyright 2017 "Valentin Popov" <[email protected]>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined("MOODLE_INTERNAL") || die();
+
+require_once(__DIR__ . "/../lib.php");
+
+/**
+ * Function to upgrade 'local_webhooks'.
+ *
+ * @param  number  $oldversion
+ * @return boolean
+ */
+function xmldb_local_webhooks_upgrade($oldversion) {
+    global $CFG, $DB;
+
+    /* Update from version 3.0.0 */
+    if ($oldversion < 2017112600) {
+        $rs = $DB->get_recordset("local_webhooks_service", null, "id", "*", 0, 0);
+        foreach ($rs as $record) {
+            if (!empty($record->events)) {
+                $record->events = unserialize(gzuncompress(base64_decode($record->events)));
+                local_webhooks_update_record($record);
+            }
+        }
+        $rs->close();
+        upgrade_plugin_savepoint(true, 2017112600, "local", "webhooks");
+    }
+
+    return true;
+}