docs: disable docs subpackage to fix FTBFS

Adressing following FTBFS on all older debian/ubuntu distros:

    Can't locate LinuxDocTools/Data/Latin1ToSgml.pm in @INC (you may need to install the LinuxDocTools::Data::Latin1ToSgml module)

distro/pkg/deb/bird2-doc.docs

-obj/doc/bird*.html
-obj/doc/bird.pdf
-obj/doc/prog*.html
-obj/doc/prog.pdf

distro/pkg/deb/control

@@ -8,11 +8,9 @@ Build-Depends: bison,
                libncurses5-dev,
                libreadline-dev | libreadline6-dev | libreadline5-dev,
                libssh-gcrypt-dev,
-               linuxdoc-tools-latex,
                m4,
                opensp,
                quilt,
-               texlive-latex-extra,
                xsltproc
 Maintainer: Jakub Ružička <jakub.ruzicka@nic.cz>
 Uploaders: Ondřej Surý <ondrej@debian.org>
@@ -31,7 +29,6 @@ Depends: adduser,
          ${misc:Depends},
          ${shlibs:Depends}
 Conflicts: bird
-Suggests: bird2-doc
 Description: Internet Routing Daemon
  BIRD is an Internet routing daemon with full support for all the major
  routing protocols. It allows redistribution between protocols with a
@@ -41,15 +38,3 @@ Description: Internet Routing Daemon
  BIRD supports IPv4 and IPv6 versions of OSPF, RIP, BGP and Babel routing
  protocols. It also supports supplementary protocols like BFD, RPKI-Router
  and IPv6 router advertisements.
-
-Package: bird2-doc
-Architecture: all
-Section: doc
-Depends: ${misc:Depends}
-Description: Internet Routing Daemon - documentation
- BIRD is an Internet routing daemon with full support for all the major
- routing protocols. It allows redistribution between protocols with a
- powerful route filtering syntax and an easy-to-use configuration
- interface.
- .
- This package provides the user and developer documentation.

distro/pkg/deb/patches/series

-0001-Sync-the-linuxdoc-mangled-files-with-linuxdoc-tools_.patch

distro/pkg/deb/rules

@@ -25,7 +25,6 @@ override_dh_auto_configure:
 
 override_dh_auto_build:
 	dh_auto_build
-	dh_auto_build -- docs
 
 override_dh_auto_install:
 	dh_auto_install --destdir=debian/tmp

distro/pkg/rpm/bird.spec

 %global _hardened_build 1
-
-%if "x%{?suse_version}" == "x"
-# missing linuxdoc-tools and sgml-common on SUSE
-%define _without_doc 1
-%endif
+%global _without_doc 1
 
 Name:             bird
 Version:          {{ version }}