mobimo/support#2982 Optimize crontab handling in production mode

src/Handler.php

@@ -515,7 +515,7 @@ class Handler extends BaseHandler {
         'condition' => $this->config->readValue(['backup', 'enable']),
       ];
       foreach ($this->config->readValue('crontabs') ?? [] as $user => $tasks) {
-        if (empty($tasks)) {
+        if (empty($tasks) || !is_array($tasks)) {
           $files[$user] = [
             'dest' => $projectRoot . '/crontabs',
             'delete' => TRUE,