ssh_execute_command failed to execute the script on ALpine

On ALpine, the docker image we use uses busybox to execute common commands like echo, ls, etc. In the ssh_execute_command function, when execv is executed, either the $SHELL variable or 'bin/bash' is stored in args[0], but in ALpine, neither is defined. Therefore, ssh_execute_command appears to be unexecutable on the ALpine platform. The recommended change is to change /bin/bash to /bin/sh so that it can run on all Linux platforms.

/bin/echo -> /bin/busybox
/bin/ed -> /bin/busybox
/bin/sh -> /bin/busybox