Use correct base64 method

aleksis/core/models.py

@@ -446,7 +446,7 @@ class Person(ContactMixin, ExtensibleModel):
         if photo is not None:
             card.append("PHOTO;ENCODING=b:")
             for chunk in photo.chunks():
-                for line in textwrap.wrap(base64.encode(chunk).decode(), 75):
+                for line in textwrap.wrap(base64.b64encode(chunk).decode(), 75):
                     card.append(" " + line)
 
         card.append("END:VCARD")