Revert "vagrant: don't try to always install python package."

This reverts commit faabfc3.

Because it fails with error "/bin/sh: 1: /usr/bin/python2.7: not found"

Author: php-coder

vagrant/provisioning/bootstrap.yml

@@ -3,21 +3,12 @@
 # Ubuntu 16.04. doesn't install python 2.x anymore and we have to install
 # it manually to be able to run Ansible playbooks.
 
-- name: Determining whether python 2.7 is installed
-  stat:
-    path: /usr/bin/python2.7
-    get_md5: no
-    get_checksum: no
-  register: python27
-
 - name: Updating packages cache
   raw: apt-get update
   become: yes
   become_method: sudo
-  when: not python27.stat.exists
 
 - name: Installing python
   raw: apt-get install -y python2.7-minimal
   become: yes
   become_method: sudo
-  when: not python27.stat.exists