I have a strange problem with mixed content after switching to SSL. I saw that all the smilies were served with http. Then I discovered that in the database in xf_smilie the image_url all had a direct link to "http". I think I did this several years ago when I was switching from vbulletin (don't ask me why, I think it was when importing my custom smilies).
The urls were changed in the database and point to https now. But still the smilies are being served with http.
I waited 6 hours now, but nothing happened. Is there any caching mechanism, which shows the old smilies?