Change health check url

Fixes #1

CloudronManifest.json

@@ -5,7 +5,7 @@
   "description": "file://DESCRIPTION.md",
   "tagline": "Transform your site into almost anything you can imagine",
   "version": "0.7.4",
-  "healthCheckPath": "/",
+  "healthCheckPath": "/wp-login.php",
   "httpPort": 8000,
   "manifestVersion": 1,
   "website": "https://wordpress.org/",