Comment 1 for bug 1673273

I took the version of Ubuntu 17.04 which has a dependency on libgnutls28-dev (>= 3.4.15). There is only version 3.4.10-4ubuntu1.2 in Ubuntu 16.04. This is why it fails to build there.

This change was made here. But I do not know the reason:
filezilla (3.24.0-1) unstable; urgency=medium

  * New upstream release
  * Updated versioned build-deps for libfilezilla-dev and libgnutls28-dev
  * Removed debian/patches/fix-build.patch

 -- Adrien Cunin <email address hidden> Tue, 17 Jan 2017 15:52:58 +0100