Fix login url failing on NoReverseMatch

Since Django 1.11 migration

wifiwithme/core/templates/registration/login.html

@@ -5,7 +5,7 @@
 {% if form.errors %}
 <p class="alert alert-danger">Mauvais utilisateur / mot de passe, essaye encore..</p>
 {% endif %}
-<form method="post" action="{% url 'django.contrib.auth.views.login' %}">
+<form method="post" action="{% url 'login' %}">
 {% csrf_token %}
   <div class="form-group">
     {{ form.username.label_tag }}