Display correct value in for inheritance in backend

Hello, 

thanks for your plugin, I could really use it.

If you select "no" as value for the inheritance of the header code and save it, the change takes effect. But if you for some other reason return to the same page later (in the admin panel) the select box displays "yes". If you do not remember to change it again to "no", you will overwrite your setting and the code will be inherited.

My changes only fix this small bug :)

Regards
Jens