replace is_staff with has_permission

[pprolancer]

Hello, @douglasmiranda

django-admin-bootstrap/bootstrap_admin/templates/admin/base.html

Line 125 in 1c837e3

{% if user.is_active and user.is_staff %}

in above line we shouldn't check accessibility with "is_staff". this cause problems for customized permission admin sites.

we should replace that line with:
{% if has_permission %}