net/rsync: Fix unexpected changes caused by previous rsync commit

• Remove python dependency introduced in last commit, we keep USES=python to fix the rrsync shebang but add PYTHON_NO_DEPENDS=yes since Python itself is not wanted. Add a pkg-message to notify users.
• Fix patching issues on manpages and sample files which abusively transformes all etc paths into /usr/local/etc.
• Install missing rrsync manpage
  
  Also add forgotten items in last commit
  • version 3.2.4 fixes CVE-2018-25032 in bundled zlib
  • remove upstreamed patch to fix time limit options (patch-io.c)

PR: 263787
PR: 263794
Reported by: <jamie@catflap.org>
Reported by: <freebsd@oldach.net>
Security: CVE-2018-25032 in the bundled zlib