Retrieve project creator's avatar by creator, not creator#email.

app/views/shared/projects/_project.html.haml

@@ -17,7 +17,7 @@
       .avatar-container.s40
         = link_to project_path(project), class: dom_class(project) do
           - if project.creator && use_creator_avatar
-            = image_tag avatar_icon(project.creator.email, 40), class: "avatar s40", alt:''
+            = image_tag avatar_icon_for_user(project.creator, 40), class: "avatar s40", alt:''
           - else
             = project_icon(project, alt: '', class: 'avatar project-avatar s40')
     .project-details