Output improvement

Hi.

When using apt-clone for the first time, the output can be misleading:

    apt-clone clone test.tar.gz
    not installable:
    version mismatch:
    Note that you can use --with-dpkg-repack to include those packges in the clone file.

There is no need to write "not installable: " with an empty list. It leaves the user with a doubt.

I checked the code to be sure this was normal output and it is:

https://sources.debian.net/src/apt-clone/0.2.2/apt-clone/

        print "not installable: %s" % ", ".join(clone.not_downloadable)
        print "version mismatch: %s" % ", ".join(clone.version_mismatch)
        if not args.with_dpkg_repack:
            print "\nNote that you can use --with-dpkg-repack to include "\
                  "those packges in the clone file."

It could be improved this way, for instance:

        if clone.not_downloadable:
                print "not installable: %s" % ", ".join(clone.not_downloadable)
        if clone.version_mismatch:
                print "version mismatch: %s" % ", ".join(clone.version_mismatch)
        if (clone.not_downloadable or clone.version_mismatch
            and not args.with_dpkg_repack):
            print "\nNote that you can use --with-dpkg-repack to include "\
                  "those packges in the clone file."

(I'm not totally sure about the conditions to test for the notice about dpkg-repack.)

Shall I submit a patch? How?

Thanks.