Fix pycodestyle issue

Author: codingjoe

django_select2/forms.py

@@ -233,7 +233,6 @@ def get_url(http://github.com/self):
 
     def build_attrs(self, base_attrs, extra_attrs=None):
         """Set select2's AJAX attributes."""
-
         default_attrs = {
             'data-ajax--url': self.get_url(),
             'data-ajax--cache': "true",