[chores] Moved CSS for allauth templates to dedicated CSS

Avoid screwing up the whole layout for a few pages.

Author: nemesifier

openwisp_users/accounts/static/openwisp-users/accounts/css/non-admin.css

@@ -0,0 +1,7 @@
+#content p {
+  margin: 10px 0;
+}
+button,
+form label {
+  margin-right: 5px;
+}

openwisp_users/accounts/templates/allauth/layouts/base.html

@@ -1,4 +1,9 @@
 {% extends "admin/base_site.html" %}
+{% load static %}
 {% block title %}OpenWISP{% endblock %}
 
+{% block extrastyle %}
+{{ block.super }}
+<link rel="stylesheet" type="text/css" href="{% static 'openwisp-users/accounts/css/non-admin.css' %}" />
+{% endblock %}
 {% block breadcrumbs %}{% endblock %}