feat: Import images correctly from OIDC claims

conduwuit-example.toml

@@ -2378,10 +2378,15 @@
 # Per-room overrides to the user's display name or avatar will be
 # preserved by the import process.
 #
-# SECURITY NOTE: If the `avatar_url` field is set, Continuwuity will
-# perform a HTTP GET to the URL in the mapped claim and use the returned
-# file as the user's profile picture. Make sure your users are not able
-# to set the value of the mapped claim to an arbitrary URL.
+# SECURITY NOTE: For the following profile fields, Continuwuity will treat
+# the value of the mapped claim as an HTTP URL and upload the file located
+# at that URL to its internal media repository:
+#
+# - `avatar_url`
+# - `chat.commet.profile_banner`
+#
+# If you map these fields to claims, make sure your users cannot set those
+# claims to arbitrary URLs.
 #
 #profile_key_map = { displayname = "name" }