curl: sync-constants.php regex and URL improvements

 - Updates the URL of Curl constant page from `https://curl.haxx.se/libcurl/c/symbols-in-versions.html`
   to `https://curl.se/libcurl/c/symbols-in-versions.html`.

 - Fixes the regex used to filter constants to match `CURL_HTTP` constants.

Related: php#12543

Author: Ayesh

ext/curl/sync-constants.php

@@ -3,12 +3,12 @@
 
 /**
  * This script checks the constants defined in the curl PHP extension, against those documented on the cURL website:
- * https://curl.haxx.se/libcurl/c/symbols-in-versions.html
+ * https://curl.se/libcurl/c/symbols-in-versions.html
  *
  * See the discussion at: https://github.com/php/php-src/pull/2961
  */
 
-const CURL_DOC_FILE = 'https://curl.haxx.se/libcurl/c/symbols-in-versions.html';
+const CURL_DOC_FILE = 'https://curl.se/libcurl/c/symbols-in-versions.html';
 
 const SOURCE_FILE = __DIR__ . '/curl_arginfo.h';
 
@@ -25,7 +25,7 @@
     'CURLOPT_SAFE_UPLOAD',
 ];
 
-const CONSTANTS_REGEX_PATTERN = '~^CURL(?:OPT|_VERSION)_[A-Z0-9_]+$~';
+const CONSTANTS_REGEX_PATTERN = '~^CURL(?:OPT|_VERSION|_HTTP)_[A-Z0-9_]+$~';
 
 /**
  * A simple helper to create ASCII tables.