fix dup keys

sc2qa_commoncrawl.py

@@ -97,8 +97,8 @@ class SC2QA(datasets.GeneratorBasedBuilder):
         key = 0
         with open(filepath, encoding="ascii", errors='ignore') as f:
             csv_reader = csv.DictReader(f)
-            for row in csv_reader:
+            for i, row in enumerate(csv_reader):
                 if split == "test": # This avoids error when doing data type converation from empty string
                     row["length bucket"] = "0"
                     row["qa classifier score"] = "0.0"
-                yield row['url'], row
+                yield i, row