fix(wlasl): rectify attributes

wlasl.py

@@ -146,10 +146,10 @@ class WLASL(datasets.GeneratorBasedBuilder):
                         "frame_end": sample["frame_end"],
                         "frame_start": sample["frame_start"],
                         "instance_id": sample["instance_id"],
-                        "signer_id": sample["singer_id"],
-                        "source": sample["signer"],
+                        "signer_id": sample["signer_id"],
+                        "source": sample["source"],
                         "url": sample["url"],
                         "variation_id": sample["variation_id"],
                         "video_id": sample["video_id"],
-                        "video": sample["video"],
+                        "video": video_path,
                     }