There are ways to remove that attribute and variation from the product, but then you won't be able to automatically process the order using the plugin (as it won't be able to match the options in your site with those in AliExpress). The only solution I came up with without going into too much detail was to source an alternative version of the product which doesn't have the other option.
The most common version of this issue I find is when products have the option selection (size for example) and then 'China' or 'Russia' as a choice of where to ship from. I just find another version of the same product which doesn't have that extra option.
If there is always only one option in the extra selection then you can set it as the default for that option in the WooCommerce product variation settings and then use CSS to hide it on the front end.