USN-2950-3: Samba regressions

USN-2950-1 fixed vulnerabilities in Samba. The fixes introduced in Samba 4.3.8 caused certain regressions and interoperability issues. This update resolves some of these issues by updating to Samba 4.3.9 in Ubuntu 14.04 LTS, Ubuntu 15.10 and Ubuntu 16.04 LTS. Backported regression fixes were adde...