Modify password reset email template to allow user configured urls

[davenaff]

This line is currently used to generate password reset urls:

{{ protocol }}://{{ domain }}/reset/{{ uid }}-{{ token }}/

This creates a fixed url in every email sent, so the user cannot customize the URL.

The proposed change is to use this line instead:

{{ protocol }}://{{ domain }}{% url django.contrib.auth.views.password_reset_confirm uidb36=uid, token=token %}

This is a single line patch so I won't upload diff files, etc.

[jacob]

Please do upload a diff; it makes the whole process quicker.

[mattmcc]

#8451 is a dup, but also has a patch.

[russellm]

(In [8517]) Fixed #8129: Modified the password reset email template to use a URL lookup, so that the email doesn't require customization based on the way that the reset view is deployed. Thanks to davenaff for the report and fix.