vagrant: upgrade openbsd box to 6.4

6.0 went out of support, the ftp server URL we used 404ed and we
already had the 6.4 box for master branch, so just use it for
1.1-maint also.

Vagrantfile

@@ -109,19 +109,14 @@ end
 
 def packages_openbsd
   return <<-EOF
-    echo 'installpath = http://ftp.hostserver.de/pub/OpenBSD/6.0/packages/amd64/' > /etc/pkg.conf
-    echo 'export PKG_PATH=http://ftp.hostserver.de/pub/OpenBSD/6.0/packages/amd64/' >> ~/.profile
-    . ~/.profile
     pkg_add bash
     chsh -s /usr/local/bin/bash vagrant
-    pkg_add openssl
     pkg_add lz4
+    pkg_add zstd
     pkg_add git  # no fakeroot
-    pkg_add py3-setuptools
-    ln -sf /usr/local/bin/python3.4 /usr/local/bin/python3
-    ln -sf /usr/local/bin/python3.4 /usr/local/bin/python
-    easy_install-3.4 pip
-    pip3 install virtualenv
+    pkg_add py3-pip
+    pkg_add py3-virtualenv
+    ln -sf /usr/local/bin/virtualenv-3 /usr/local/bin/virtualenv
   EOF
 end
 
@@ -543,7 +538,7 @@ Vagrant.configure(2) do |config|
   end
 
   config.vm.define "openbsd64" do |b|
-    b.vm.box = "openbsd60-64"  # note: basic openbsd install for vagrant WITH sudo and rsync pre-installed
+    b.vm.box = "openbsd64-64"  # note: basic openbsd install for vagrant WITH sudo and rsync pre-installed
     b.vm.provider :virtualbox do |v|
       v.memory = 1024 + $wmem
     end