Fix caching of the user avatar
Fix caching of the user avatar

Now on firefox/safari it is only refetched once a day. On Chrom{e,ium}
we keep the previous behavior of maybe refetching it more often.

This also notify the user about this behavior when they upload an avatar
picture.

Signed-off-by: Carl Schwan <de187642e6c75f60d10f29e52cab54cdf676870d@carlschwan.eu>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server