s/username/clipper in highlight_clipper

There was typo, the `Clipper` object has no `username` attribute. We
want to use the `clipper` attribute

kfet/templatetags/kfet_tags.py

@@ -1,23 +1,21 @@
 # -*- coding: utf-8 -*-
 
-from __future__ import (absolute_import, division,
-                        print_function, unicode_literals)
-from builtins import *
-
 from django import template
 from django.utils.html import escape
 from django.utils.safestring import mark_safe
-from django.core.cache import cache
 from kfet.models import Settings
 from math import floor
 import re
 
 register = template.Library()
 
+
 def highlight_text(text, q):
     q2 = "|".join(q.split())
     pattern = re.compile(r"(?P<filter>%s)" % q2, re.IGNORECASE)
-    return mark_safe(re.sub(pattern, r"<span class='highlight_autocomplete'>\g<filter></span>", text))
+    regex = r"<span class='highlight_autocomplete'>\g<filter></span>"
+    return mark_safe(re.sub(pattern, regex, text))
+
 
 @register.filter(is_safe=True)
 def highlight_user(user, q):
@@ -27,14 +25,16 @@ def highlight_user(user, q):
         text = user.username
     return highlight_text(escape(text), q)
 
+
 @register.filter(is_safe=True)
 def highlight_clipper(clipper, q):
     if clipper.fullname:
-        text = "%s (%s)" % (clipper.fullname, clipper.username)
+        text = "%s (%s)" % (clipper.fullname, clipper.clipper)
     else:
-        text = clipper.username
+        text = clipper.clipper
     return highlight_text(escape(text), q)
 
+
 @register.filter()
 def ukf(balance, is_cof):
     grant = is_cof and (1 + Settings.SUBVENTION_COF() / 100) or 1