{% load i18n %}{% block subject %}{% endblock %}
{% block greeting %}{% trans "Hello" %} {{ user.get_short_name }},{% endblock %}
{% block notification %}{% endblock %}
{% trans "Edit your notification preferences here:" %} {{ settings.BASE_URL }}{% url 'wagtailadmin_account_notification_preferences' %}

{% load i18n %}{% block subject %}{% endblock %}
{% block greeting %}{% trans "Hello" %} {{ user.get_short_name|default:user.get_username }},{% endblock %}
{% block notification %}{% endblock %}
{% trans "Edit your notification preferences here:" %} {{ settings.BASE_URL }}{% url 'wagtailadmin_account_notification_preferences' %}

Make "Hello" part of notification emails use user's username if we don't know their real name
Make "Hello" part of notification emails use user's username if we don't know their real name
