[1.5.x] Fixed #19606 -- Adjusted cx_Oracle unicode detection.
[1.5.x] Fixed #19606 -- Adjusted cx_Oracle unicode detection.

Backpatch of d194f290571f7e9dda7d2fd7a6f2b171120f2f14

imtapps/django-imt-fork,bliti/django-nonrel-1.5,alx-eu/django,hasadna/django,alx-eu/django,bliti/django-nonrel-1.5,imtapps/django-imt-fork,ccn-2m/django,hasadna/django,ccn-2m/django,ccn-2m/django,alx-eu/django,ccn-2m/django,imtapps/django-imt-fork,alx-eu/django,bliti/django-nonrel-1.5,hasadna/django