Error with `embed` when passing a List

```python
from llama_cpp import Llama

# This works
llm = Llama(model_path="/tmp/all-MiniLM-L6-v2-Q8_0.gguf", embedding=True)
print(llm.embed(["test"]))

# This also works
import numpy as np
print(np.array([llm.embed(x) for x in ["test", "test"]]))

# This fails
llm = Llama(model_path="/tmp/all-MiniLM-L6-v2-Q8_0.gguf", embedding=True)
print(llm.embed(["test", "test"]))
```