Fix initial ping for new healthckecks

src/Handler.php

@@ -526,7 +526,7 @@ class Handler extends BaseHandler {
       ];
 
       // Manage crontabs and optionally add them to heathcheck-io.
-      $hj_url = getenv('HEALTHCHECK_API_URL');
+      $hj_url = getenv('HEALTHCHECK_URL');
       $hj_api_key = getenv('HEALTHCHECK_API_KEY');
       $hj_api_channels = getenv('HEALTHCHECK_API_CHANNELS');
       $hj_project = $this->config->readValue('projectname');