Revert "Fix breaking bug in save.py with interpreting quantization_method as …" (#652)

This reverts commit 30605de.

Author: danielhanchen

unsloth/save.py

@@ -853,13 +853,9 @@ def save_to_gguf(
     model_dtype = "f16" if model_dtype == "float16" else "bf16"
 
     # Convert quantization_method to list
-    if   isinstance(quantization_method, list):  pass
-    elif isinstance(quantization_method, str):   quantization_method = [ quantization_method, ]
-    elif isinstance(quantization_method, tuple): quantization_method = list(quantization_method)
-    else:
-        raise TypeError("Unsloth: quantization_method can only be a string or a list of strings")
-    pass
-    
+    quantization_method = \
+        quantization_method if type(quantization_method) is list else list(quantization_method)
+
     # Check if bfloat16 is supported
     if model_dtype == "bf16" and not torch.cuda.is_bf16_supported():
         logger.warning(