utils/validate/ssh.py: rm unused import of CommandExecutionError
utils/validate/ssh.py: rm unused import of CommandExecutionError

************* Module salt.utils.validate.ssh
salt/utils/validate/ssh.py:14: [W0611(unused-import), ] Unused import CommandExecutionError
saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt