Update pip.yml

Install pip only if it was downloaded from https://bootstrap.pypa.io.
Do not try to install the pip package when you re-run this playbook.

tasks/pip.yml

@@ -10,10 +10,12 @@
         dest: /tmp/
         timeout: 30
         validate_certs: no
+      register: get_pip_result
 
     - name: pip | install pip
       command: python3 get-pip.py --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org
       args:
         chdir: /tmp/
+      when: get_pip_result.changed
   environment: '{{ proxy_env | default({}) }}'
   tags: [ pip_install, pip ]