Ensure User.avatar is optional

entries/jinja2/entries/h-entry.html

@@ -3,7 +3,7 @@
 <article class="h-entry media">
   {{i}}<aside class="info">
     {{i}}<a class="p-author h-card" href="{{ entry.author.url }}">
-      {{i}}<img class="u-photo img-fluid" src="{{ entry.author.avatar.url }}" alt="{{ entry.author.name }}" />
+      {{i}}{% if entry.author.avatar %}<img class="u-photo img-fluid" src="{{ entry.author.avatar.url }}" alt="{{ entry.author.name }}" />{% endif %}
       {{i}}<span class="p-name sr-only">{{ entry.author.name }}</span>
     {{i}}</a>
     {{i}}<a class="u-uid u-url" href="{{ entry.url }}">

users/models.py

@@ -128,7 +128,7 @@ class User(ModelMeta, AbstractUser):
 
     @property
     def avatar_url(self):
-        return self.avatar.url
+        return self.avatar.url if self.avatar else None
 
     @cached_property
     def facebook_id(self):
@@ -154,7 +154,7 @@ class User(ModelMeta, AbstractUser):
             "url": self.full_url,
             "name": self.name,
             "email": self.email,
-            "image": urljoin(base, self.avatar.url),
+            "image": urljoin(base, self.avatar.url) if self.avatar else None,
             "givenName": self.first_name,
             "familyName": self.last_name,
             "sameAs": [profile.url for profile in self.profiles.all()],