fix: chat stream returns an error response with a 'data: ' prefix

[liushuangls]

Occasionally, OpenAI may return the following error message:

data: {"error":{"message":"The server experienced an error while processing your request. We apologize for the inconvenience!", "type":"server_error", "param":null,"code":null)}

data: [DONE]

In such cases, the stream.Recv() function will return a successful status along with a zero-value response.

[codecov]

Codecov Report

Merging #396 (abfcd5e) into master (b095938) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #396      +/-   ##
==========================================
+ Coverage   95.26%   95.32%   +0.05%     
==========================================
  Files          17       17              
  Lines         676      684       +8     
==========================================
+ Hits          644      652       +8     
  Misses         22       22              
  Partials       10       10              

Impacted Files	Coverage Δ
stream_reader.go	100.00% <100.00%> (ø)

[sashabaranov]

Awesome, thank you!

[liushuangls]

@sashabaranov Please release it.

[pmilanez]

+1 for release it, i'm facing this problem and not been able to retry it based on the error