Fix random_seed overflow when seeds per model > 1.

PiperOrigin-RevId: 429520386
Change-Id: Ic1ba2b31e25a0511fefe5d0d462fc5a218641a56

run_alphafold.py

@@ -418,7 +418,7 @@ def main(argv):
 
   random_seed = FLAGS.random_seed
   if random_seed is None:
-    random_seed = random.randrange(sys.maxsize // len(model_names))
+    random_seed = random.randrange(sys.maxsize // len(model_runners))
   logging.info('Using random seed %d for the data pipeline', random_seed)
 
   # Predict structure for each of the sequences.