Wonders won't need to be adjacent to district but they will still require one.
Side effect: they won't show on the construction list unless you already have the required district.
You can download the mod and use it or just use this sql update:
UPDATE Buildings SET PrereqDistrict = AdjacentDistrict, AdjacentDistrict = NULL WHERE MaxWorldInstances == 1 AND AdjacentDistrict IS NOT NULL;
Side effect: they won't show on the construction list unless you already have the required district.
You can download the mod and use it or just use this sql update:
UPDATE Buildings SET PrereqDistrict = AdjacentDistrict, AdjacentDistrict = NULL WHERE MaxWorldInstances == 1 AND AdjacentDistrict IS NOT NULL;