nope. use it as is.
Note: make sure to use version of the skin that matches the Roundcube version. If it is not available use the closest lower version number. For example, if your Roundcube version is 1.6.5, use skin version 1.6.x (with max X that exists), if 1.6.x does not exist use 1.5.x and so on. Using 1.7.x and up might not work.
also as we are using root you might alter a little the command for it to work