PEP8 cleanups.

mayan/apps/document_indexing/apps.py

@@ -15,7 +15,6 @@ from common import (
     menu_setup, menu_tools
 )
 from common.classes import Package
-from common.signals import post_initial_setup
 from common.widgets import two_state_template
 from documents.signals import post_document_created, post_initial_document_type
 from mayan.celery import app

mayan/apps/document_indexing/handlers.py

@@ -3,8 +3,6 @@ from __future__ import unicode_literals
 from django.apps import apps
 from django.utils.translation import ugettext_lazy as _
 
-from documents.literals import DEFAULT_DOCUMENT_TYPE_LABEL
-
 from .tasks import task_delete_empty_index_nodes, task_index_document