reverted a docstring example change in onset_detect
reverted a docstring example change in onset_detect

ruohoruotsi/librosa,stefan-balke/librosa,carlthome/librosa,r9y9/librosa,ruohoruotsi/librosa,carlthome/librosa,stefan-balke/librosa,ruohoruotsi/librosa,r9y9/librosa,carlthome/librosa,r9y9/librosa,stefan-balke/librosa