bugfix escaping " in type __key_value for 3.0.0

Hello nico, 
i have a file in wich we have values like "@sdba hard nofile 131200",
in 2.3.7 this was working with the --value '"@sdba hard nofile 131200"',
in 3.0.0 the remote sed was wrong escaped.

After some try around, this patch fixes so i can set values again to values with a " in it ...