Use correct file mode for client key.
Use correct file mode for client key.

Client key needs to be group-readable, but server key must not be.  Correctly
set file mode based on server bool.

google/stenographer,gconnell/stenographer,nbareil/stenographer,dcode/stenographer,gconnell/stenographer,dcode/stenographer,dcode/stenographer,gconnell/stenographer,google/stenographer,nbareil/stenographer,nbareil/stenographer,google/stenographer