Use SCRIPT_NAME instead of REQUEST_URI to check path

The script is currently checking if the `REQUEST_URI` is containing
`wp-comments-post.php`, the default script to handle the submission
of a comment. Some security plugins have options to rename this file
to disguise that WordPress is used.

With this fix, the `SCRIPT_NAME` is used instead. Since many security
plugins do use rewrite rules, while the `REQUEST_URI` value is changed,
the `SCRIPT_NAME` value stays the same. Therefore the condition would
still recognize if a comment was submitted.

Fixes #585

antispam_bee.php

@@ -1134,7 +1134,7 @@ public static function precheck_incoming_request() {
 			return;
 		}
 
-		$request_uri  = self::get_key( $_SERVER, 'REQUEST_URI' );
+		$request_uri  = self::get_key( $_SERVER, 'SCRIPT_NAME' );
 		$request_path = self::parse_url( $request_uri, 'path' );
 
 		if ( strpos( $request_path, 'wp-comments-post.php' ) === false ) {
@@ -1168,7 +1168,7 @@ public static function precheck_incoming_request() {
 	public static function handle_incoming_request( $comment ) {
 		$comment['comment_author_IP'] = self::get_client_ip();
 
-		$request_uri  = self::get_key( $_SERVER, 'REQUEST_URI' );
+		$request_uri  = self::get_key( $_SERVER, 'SCRIPT_NAME' );
 		$request_path = self::parse_url( $request_uri, 'path' );
 
 		if ( empty( $request_path ) ) {