(legacy) remove caching of filter interfaces, likely suspect of...

(legacy) remove caching of filter interfaces, likely suspect of https://github.com/opnsense/core/issues/451

(cherry picked from commit 288bc8cb)

src/etc/inc/filter.inc

@@ -870,12 +870,6 @@ function filter_generate_optcfg_array()
 {
     global $config, $FilterIflist;
 
-    // Nasty hack to avoid unkown status of $FilterIflist, every piece of code using $FilterIflist should use
-    // this function to retrieve it's content.
-    if (isset($FilterIflist) && is_array($FilterIflist) && count($FilterIflist) > 0) {
-        return $FilterIflist;
-    }
-
     $FilterIflist = array();
 
     /* if list */