I had the problem, that after changing the server-url on my StatusNet installation all avatars were broken, because the linked to the non-https version of the site.
Nothing but the following worked:
execute
Source: http://forum.status.net/discussion/788/ssl-always-but-http-avatar-links
Kommentar(e):
Nothing but the following worked:
execute
Source: http://forum.status.net/discussion/788/ssl-always-but-http-avatar-links
Kommentar(e):

Hi there friends, nice post and nice arguments commented here, I am actually enjoying by
these.