Remove the variable redefined in deploy-servers.yml

The 'ansible_python_interpreter' has already defined in /etc/bifrost/bifrost.yml
we should remove the redundant variable

Change-Id: Ie799170d3318a731d31e1f39bcf940a1b220bd53

ansible/roles/bifrost/tasks/deploy-servers.yml

@@ -6,8 +6,7 @@
      && source /opt/stack/ansible/hacking/env-setup &&
      export BIFROST_INVENTORY_SOURCE=/etc/bifrost/servers.yml &&
      ansible-playbook -vvvv -i /bifrost/playbooks/inventory/bifrost_inventory.py
-     /bifrost/playbooks/enroll-dynamic.yaml -e "ansible_python_interpreter=/var/lib/kolla/venv/bin/python"
-     -e @/etc/bifrost/bifrost.yml'
+     /bifrost/playbooks/enroll-dynamic.yaml -e @/etc/bifrost/bifrost.yml'
 
 - name: Deploy physical servers with ironic
   command: >
@@ -16,5 +15,4 @@
      && source /opt/stack/ansible/hacking/env-setup &&
      export BIFROST_INVENTORY_SOURCE=/etc/bifrost/servers.yml &&
      ansible-playbook -vvvv -i /bifrost/playbooks/inventory/bifrost_inventory.py
-     /bifrost/playbooks/deploy-dynamic.yaml -e "ansible_python_interpreter=/var/lib/kolla/venv/bin/python"
-     -e @/etc/bifrost/bifrost.yml'
+     /bifrost/playbooks/deploy-dynamic.yaml -e @/etc/bifrost/bifrost.yml'