Update stream.cpp

[AliAlameh]

#445 fix Language auto-detect "auto" flag does not work using the stream tool

[ggerganov]

This way, the stream example will keep on auto-detecting the language forever.

Maybe it would be better after it auto-detects the spoken language to select it explicitly in order to avoid running the "auto-detect" code

[gourcetools]

Thank you, please merge.