[Wan2.1-FLF2V] update conversion script (#11365)

update scheuler config in conversion sript

Author: yiyixuxu

scripts/convert_wan_to_diffusers.py

@@ -433,8 +433,9 @@ def get_args():
     vae = convert_vae()
     text_encoder = UMT5EncoderModel.from_pretrained("google/umt5-xxl")
     tokenizer = AutoTokenizer.from_pretrained("google/umt5-xxl")
+    flow_shift = 16.0 if "FLF2V" in args.model_type else 3.0
     scheduler = UniPCMultistepScheduler(
-        prediction_type="flow_prediction", use_flow_sigmas=True, num_train_timesteps=1000, flow_shift=3.0
+        prediction_type="flow_prediction", use_flow_sigmas=True, num_train_timesteps=1000, flow_shift=flow_shift
     )
 
     if "I2V" in args.model_type or "FLF2V" in args.model_type: