Always unset X-Powered-By header (#184)

as per #183, `always` can be used to ensure the directive is always applied. In this case should be a sensed default.

Fix #183

Author: GlassGruber

src/security/x-powered-by.conf

@@ -19,5 +19,5 @@
 # https://php.net/manual/en/ini.core.php#ini.expose-php
 
 <IfModule mod_headers.c>
-    Header unset X-Powered-By
+    Header always unset X-Powered-By
 </IfModule>