esipa_rest_utils: fix searchCritera.profileClass type conversion
We currently use utils:hex_to_integer to convert the ProfileClass, which is supposedly a string, to integer. However, hex_to_inteteger does not exist and when looking into the related JSON schema definition of we see that the profileClass member is already defined as integer. This means that ProfileClass already arrives as integer and can be used as it is. removing the hex_to_integer call solves the problem.
