Removed unnecessary registration of psycopg2 unicode extensions on Python 3

django/db/backends/postgresql/base.py

@@ -12,6 +12,7 @@ from django.db import DEFAULT_DB_ALIAS
 from django.db.backends.base.base import BaseDatabaseWrapper
 from django.db.backends.base.validation import BaseDatabaseValidation
 from django.db.utils import DatabaseError as WrappedDatabaseError
+from django.utils import six
 from django.utils.encoding import force_str
 from django.utils.functional import cached_property
 from django.utils.safestring import SafeBytes, SafeText
@@ -47,8 +48,9 @@ from .version import get_version                            # NOQA isort:skip
 DatabaseError = Database.DatabaseError
 IntegrityError = Database.IntegrityError
 
-psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
-psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
+if six.PY2:
+    psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
+    psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
 psycopg2.extensions.register_adapter(SafeBytes, psycopg2.extensions.QuotedString)
 psycopg2.extensions.register_adapter(SafeText, psycopg2.extensions.QuotedString)
 psycopg2.extras.register_uuid()