rebind: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/rebind - from package: websockify

You may install the required package with command apt-get install {package}
Error in other languages:
rebind: bevel nie gevind nie
rebind: comandă negăsită
rebind: comando não encontrado
rebind: commande introuvable
rebind: command not found
rebind: käsku ei ole
rebind: không tìm thấy lệnh
rebind: komanda nerasta
rebind: Kommando nicht gefunden.
rebind: kommandot finns inte
rebind: komut yok
rebind: nie znaleziono polecenia
rebind: níor aimsíodh an t-ordú
rebind: no se encontró la orden
rebind: no s'ha trobat l'ordre
rebind: opdracht niet gevonden
rebind: parancs nem található
rebind: perintah tidak ditemukan
rebind: príkaz nenájdený
rebind: příkaz nenalezen
rebind: команда не найдена
rebind: командата не е открита
rebind: 命令找不到
rebind: コマンドが見つかりません