AzureChatOpenAI Streaming causes IndexError: list index out of range

### System Info
langchain-0.0.205-py3, macos ventura, python 3.11

### Who can help?
@hwchase17 / @agola11 

### Information
- [x] The official example notebooks/scripts
https://python.langchain.com/docs/modules/model_io/models/chat/how_to/streaming

### Related Components
- [X] LLMs/Chat Models

### Reproduction

### Reproduction code
```python
# test.py
from langchain.chat_models import AzureChatOpenAI
from langchain.chat_models import ChatOpenAI
from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
from langchain.schema import (
    HumanMessage,
)


chat_1 = ChatOpenAI(streaming=True, 
                  callbacks=[StreamingStdOutCallbackHandler()],
                  openai_api_key="SOME-KEY",
                  model='gpt-3.5-turbo',
                  temperature=0.7, 
                  request_timeout=60,
                  max_retries=1)


chat_2 = AzureChatOpenAI(streaming=True, 
                       callbacks=[StreamingStdOutCallbackHandler()],
                       openai_api_base="https://some-org-openai.openai.azure.com/",
                       openai_api_version="2023-06-01-preview",
                       openai_api_key="SOME-KEY",
                       deployment_name='gpt-3_5',
                       temperature=0.7, 
                       request_timeout=60,
                       max_retries=1)

resp_1 = chat_1([HumanMessage(content="Write me a song about sparkling water.")])
resp_2 = chat_2([HumanMessage(content="Write me a song about sparkling water.")])
```

```shell
python test.py
```

### Output of command 1 (OpenAI)
```shell
Verse 1:
Bubbles dancing in my cup
Refreshing taste, can't get enough
Clear and crisp, it's always there
A drink that's beyond compare

Chorus:
Sparkling water, oh how you shine
You make my taste buds come alive
With every sip, I feel so fine
Sparkling water, you're one of a kind

Verse 2:
A drink that's light and calorie-free
A healthier choice, it's plain to see
A perfect thirst quencher, day or night
With sparkling water, everything's right

Chorus:
Sparkling water, oh how you shine
You make my taste buds come alive
With every sip, I feel so fine
Sparkling water, you're one of a kind

Bridge:
From the fizzy sensation to the bubbles popping
You're the drink I never want to stop sipping
Whether at a party or on my own
Sparkling water, you're always in the zone

Chorus:
Sparkling water, oh how you shine
You make my taste buds come alive
With every sip, I feel so fine
Sparkling water, you're one of a kind

Outro:
Sparkling water, you're my go-to
A drink that always feels brand new
With each sip, I'm left in awe
Sparkling water, you're the perfect beverage 
```


### Output of command 2 (Azure OpenAI)
```shell
raw.Traceback (most recent call last):
  File "/Users/someone/Development/test.py", line 29, in <module>
    resp_2 = chat_2([HumanMessage(content="Write me a song about sparkling water.")])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/langchain/chat_models/base.py", line 208, in __call__
    generation = self.generate(
                 ^^^^^^^^^^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/langchain/chat_models/base.py", line 102, in generate
    raise e
  File "/opt/homebrew/lib/python3.11/site-packages/langchain/chat_models/base.py", line 94, in generate
    results = [
              ^
  File "/opt/homebrew/lib/python3.11/site-packages/langchain/chat_models/base.py", line 95, in <listcomp>
    self._generate(m, stop=stop, run_manager=run_manager, **kwargs)
  File "/opt/homebrew/lib/python3.11/site-packages/langchain/chat_models/openai.py", line 334, in _generate
    role = stream_resp["choices"][0]["delta"].get("role", role)
           ~~~~~~~~~~~~~~~~~~~~~~^^^
IndexError: list index out of range
```

### Expected behavior

I can't find anything in existing issues or documentation stating that there is a known bug in the AzureOpenAI Service Streaming.