defined('CLEANCACHE_HOURS') (#5144)

https://github.com/FreshRSS/FreshRSS/issues/4627

constants.php

@@ -57,3 +57,6 @@ defined('EXTENSIONS_PATH') or define('EXTENSIONS_PATH', FRESHRSS_PATH . '/extens
 
 //Directory used for feed mutex with *.freshrss.lock files. Must be writable.
 defined('TMP_PATH') or define('TMP_PATH', sys_get_temp_dir());
+
+//clean the chacke after x hours (720 hours = 30 days)
+defined('CLEANCACHE_HOURS') or define('CLEANCACHE_HOURS', 720);

lib/lib_rss.php

@@ -434,7 +434,7 @@ function httpGet(string $url, string $cachePath, string $type = 'html', array $a
 	}
 
 	if (mt_rand(0, 30) === 1) {	// Remove old entries once in a while
-		cleanCache();
+		cleanCache(CLEANCACHE_HOURS);
 	}
 
 	if (FreshRSS_Context::$system_conf->simplepie_syslog_enabled) {