relax permissions on /etc/ssh and files

root can write anyway, even if the permissions strictly speaking doesn't allow this. moreover, we want root to write, in the default DAC based model, so open this up slightly

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
Merge pull request #11 from TelekomLabs/relax-permissions

relax permissions on /etc/ssh and files