Remove encoding header

Fixes #2996

InvenTree/plugin/api.py

@@ -2,9 +2,6 @@
 JSON API for the plugin app
 """
 
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 from django.conf import settings
 from django.urls import include, re_path
 

InvenTree/plugin/base/event/events.py

@@ -2,9 +2,6 @@
 Functions for triggering and responding to server side events
 """
 
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 import logging
 
 from django.conf import settings

InvenTree/plugin/models.py

@@ -2,8 +2,6 @@
 Plugin model definitions
 """
 
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 import warnings
 
 from django.utils.translation import gettext_lazy as _

InvenTree/plugin/serializers.py

@@ -2,9 +2,6 @@
 JSON serializers for plugin app
 """
 
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 import os
 import subprocess