Fixed errors appearing in console when creating shops for 1.11 items that I have not added to the defaults yet. These items will now be set to the default price. In order to add defaults for them yourself, use /ifs setdefaultprice [price] while having the item in your hand. I will be uploading a new update when all of those have been added later on. (I depend on a third party service to do this)
Optimised some parts of the plugin, no noticeable changes.