Only show local part of the email address in the Profile page title (m…

…ozilla#3446)

The motivation for this change is that we currently publicly show the email address of a user that doesn't have any contributions yet, but our Terms of Use say "Your name and email address, or a derivative of it, may be attached to your *contributions* and so be visible worldwide".

Note that we show the custom display name in the Profile page title for users that set it.

pontoon/contributors/templates/contributors/profile.html

@@ -3,7 +3,7 @@
 
 {% extends "base.html" %}
 
-{% block title %}{{ contributor.name_or_email }}{% endblock %}
+{% block title %}{{ contributor.display_name }}{% endblock %}
 
 {% block before %}
 <!-- Server data -->