(version 0.4) fix: github issue #3 (if not set per service ignore)

* only apply wrapper if a value is provided
* also fixed kinda dumb default root application

https://github.com/zaus/forms-3rdparty-xpost/issues/3

git-svn-id: https://plugins.svn.wordpress.org/forms-3rd-party-xpost/trunk@1048843 b8457f37-d9ea-0310-8a92-e5e31aec5664