Revert "Merge pull request #1544 from kongove/disable-ssh-debug"

This reverts commit da68c016be1d0f27d7d269949b8b4072a8cda471, reversing
changes made to a9cce5c525271af65e0ce6354c70a8983417a6e6.
Revert "virttest: Add debug option to ssh and dhclient command"

This reverts commit b596354972eecafdcc493577eeaf9d3d4e51c744.
Merge pull request #1548 from autotest/fix-ssh-mess

Fix ssh mess