server : automatically convert audio on the server (#1539)

server : automatically convert audio on the server (#1539)

* server : automatically convert audio on the server

* server : remove rebundant comments

* server : automatic conversion refactor

* server : update server readme

* server : remove unnecessary comments and tabs

* server : put back remove calling

* server : apply suggestions from code review

Co-authored-by: Georgi Gerganov <redacted>
* server : check ffmpeg before the server lunch

* server : fix indentation

* Apply suggestions from code review

Co-authored-by: Georgi Gerganov <redacted>
* server : fix function typo calling

* server : fix function typo calling

* server : add warning in readme

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Co-authored-by: Georgi Gerganov <redacted>