This update for bird fixes the following issues:

- redownload sources, seem like they changed a little

- Minor polishing
  * use %tmpfiles_create macro
  * use install -D instead of mkdir && install 

- Update to version 2.17.1
  * BSD: Fix build on NetBSD
  * BGP: Fix crash when incoming connection for disabled protocol arrives
  * Documentation fixes
- Drop extra spaces in sysusers file and drop explicit group creation
- Use prebuild PDF documentation for the docs package

- Drop explicit User & Group Provides, should be handled automatically

- Drop perl dependency for docs package because:
  * we currently don't build the documentation
  * real dependencies are different anyway

- Update description
- Migrate user creation to sysuser-tools

- Update to version 2.17
  * Babel: next hop control for IPv4
  * BGP: link-local next hop format configuration
  * TCP-AO implementation for Linux

- Update to version 2.16
  * BFD: Set password per session
  * BFD: Accept zero checksum for IPv6-UDP
  * BMP: Refactoring and optimizations
  * OSPF: Allow loopback nexthop in OSPFv3-IPv4
  * RPKI: TCP-MD5 authentication option
  * Filters: Add enum types to filter grammar
  * CLI: Configurable additional control sockets
  * CLI: Timeformat command
  * CLI: Dump commands need a target file
  * ASPA support in filters, Static and RPKI
  * Formalized contributions and credits policy
  * Many bugfixes and improvements