fix flake8 errors

rca/images/models.py

@@ -1,4 +1,3 @@
-from django.conf import settings
 from django.db import models
 from wagtail.api import APIField
 from wagtail.images.models import AbstractImage, AbstractRendition, Image

rca/people/admin/page_import_forms.py

@@ -1,5 +1,4 @@
 from django import forms
-from django.contrib import admin
 from django.contrib.admin.widgets import AutocompleteSelect
 from django.contrib.auth import get_user_model
 from import_export.forms import ConfirmImportForm, ImportForm