FIX 'NoneType' object has no attribute 'isalpha' (#2440)

passerbya

2025-03-20 5ee2f382b32c5c0beaa1c133b466a100c6fb7ebc

 examples/industrial_data_pretraining/llm_asr/demo_speech2text.sh

@@ -62,4 +62,3 @@

}&
done
wait