Fixed the way of changing encrypted password string.
Fixed the way of changing encrypted password string.

I had a advice of better implementation in FreeBSD workshop, Tokyo.

verisign/specinfra,mizzy/specinfra,sergueik/specinfra,ihassin/specinfra,stefanhorning/specinfra,minimum2scp/specinfra,serverspec/specinfra,uroesch/specinfra