{% load i18n static %}
<div class="related-widget-wrapper">
    <div>{{ widget }}</div>
    <div>
    {% spaceless %}
    {% for model in model_choices %}
    <a  href="{{model.related_url}}"
        class="related-widget-wrapper-link add-related" id="add_id_content"
        alt="{{model.label}}">
        <span id="add_id_{{name}}" data-original-title>{{model.label}}</span>
    </a><span> / </span>
    {% endfor %}
    {% endspaceless %}
    </div>
</div>

{% load i18n static %}
<div class="related-widget-wrapper">
    <div>{{ widget }}</div>
    <div>
    {% spaceless %}
    {% for model in model_choices %}
    <a  href="{{model.related_url}}"
        class="related-widget-wrapper-link add-related" id="add_id_content"
        alt="{{model.label}}">
        <span id="add_id_{{name}}" data-original-title>{{model.label}}</span>
    </a>
    {% if model != model_choices|last %}<span> / </span>{% endif %}
    {% endfor %}
    {% endspaceless %}
    </div>
</div>

Fix default template for one to one widget final slash
Fix default template for one to one widget final slash
