fix import skip

tests/rest/client/test_media.py

@@ -168,10 +168,10 @@ def test_remote_media_thumbnail_normally_unblocked(self) -> None:
 
 
 class UnstableURLPreviewTests(unittest.HomeserverTestCase):
-    servlets = [media.register_servlets]
     if not lxml:
         skip = "url preview feature requires lxml"
 
+    servlets = [media.register_servlets]
     hijack_auth = True
     user_id = "@test:user"
     end_content = (