Fix id_carrier check on module

[firstred]

Questions	Answers
Branch?	develop
Description?	Should use property_exists instead of array_key_exists. The current "hack" somehow still works, but we aren't checking an array, but rather an object instead. In order to future-proof the code we should use the right method. I even consider it a bug, because by the grace of PHP it still works, but this could end one day 😉
Type?	bug fix
Category?	CO
BC breaks?	no
Deprecations?	no
Fixed ticket?	N/A
How to test?	Generate a CarrierModule @ https://validator.prestashop.com and check if the module still works