Increase compatibility level in debian/compat to allow building debs on new Ubuntu versions

[Melnorme1984]

Since you're in the business of fixing curlftpfs bugs that the official Ubuntu distro won't, maybe you could take care of this issue as well: https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1929066.html

[JackSlateur]

Hello @Melnorme1984 Thank you for your report, the change has been merged