Documents, Mailer: Sort imports, minor style fix

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/documents/settings.py

@@ -8,7 +8,8 @@ from django.utils.translation import ugettext_lazy as _
 from mayan.apps.smart_settings import Namespace
 
 from .literals import (
-    DEFAULT_DOCUMENTS_CACHE_MAXIMUM_SIZE, DEFAULT_LANGUAGE, DEFAULT_LANGUAGE_CODES
+    DEFAULT_DOCUMENTS_CACHE_MAXIMUM_SIZE, DEFAULT_LANGUAGE,
+    DEFAULT_LANGUAGE_CODES
 )
 from .utils import callback_update_cache_size