Describe the bug
On many servers, including those at InMotion Hosting, the $_SERVER['SERVER_NAME'] constant is not defined, generating warnings in debug logs and WP-CLI output:

Notice: Undefined index: SERVER_NAME in /home/username23/public_html/wp-content/plugins/post-and-page-builder/includes/config/config.plugin.php on line 18

Expected Behavior
The plugin should check if the constant is defined before using it.