fix lint issues

rest_framework/fields.py

@@ -8,14 +8,11 @@ import inspect
 import re
 import uuid
 
-import django
 from django.conf import settings
 from django.core.exceptions import ValidationError as DjangoValidationError
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.validators import RegexValidator, ip_address_validators
-from django.forms import (
-    ImageField as DjangoImageField, FilePathField as DjangoFilePathField
-)
+from django.forms import ImageField as DjangoImageField
 from django.utils import six, timezone
 from django.utils.dateparse import parse_date, parse_datetime, parse_time
 from django.utils.encoding import is_protected_type, smart_text