Move import inside response method

This is not idiomatic, but I don't see another neat way to move it out
of the top level and still handle testing / other situations where the
settings are modified on-the-fly.

dj_rest_auth/views.py

@@ -12,20 +12,6 @@ from rest_framework.permissions import AllowAny, IsAuthenticated
 from rest_framework.response import Response
 from rest_framework.views import APIView
 
-if getattr(settings, 'REST_USE_JWT'):
-    from rest_framework_simplejwt.exceptions import TokenError
-    from rest_framework_simplejwt.tokens import RefreshToken
-else:
-    # NOTE: these are not actually used except if `REST_USE_JWT` is True, but
-    # ensuring they're defined anyway in case
-
-    class TokenError(Exception):
-        pass
-
-    class RefreshToken:
-        pass
-
-
 from .app_settings import (JWTSerializer, LoginSerializer,
                            PasswordChangeSerializer,
                            PasswordResetConfirmSerializer,
@@ -154,6 +140,13 @@ class LogoutView(APIView):
                             status=status.HTTP_200_OK)
 
         if getattr(settings, 'REST_USE_JWT', False):
+            # NOTE: this import occurs here rather than at the top level
+            # because JWT support is optional, and if `REST_USE_JWT` isn't
+            # True we shouldn't need the dependency
+            from rest_framework_simplejwt.exceptions import TokenError
+            from rest_framework_simplejwt.tokens import RefreshToken
+
+
             cookie_name = getattr(settings, 'JWT_AUTH_COOKIE', None)
             if cookie_name:
                 response.delete_cookie(cookie_name)