supervisor-xqueue: Fix activation of virtualenv for ease installation

Source the `activate` file instead of attempting to execute it, which requires
execution rights.

playbooks/roles/ora/tasks/ease.yml

@@ -54,7 +54,7 @@
 
 - name: ora | install ease python package
   shell: >
-    {{ ora_ease_venv_dir }}/bin/activate; cd {{ ora_ease_code_dir }}; python setup.py install
+    . {{ ora_ease_venv_dir }}/bin/activate; cd {{ ora_ease_code_dir }}; python setup.py install
   sudo_user: "{{ ora_user }}"
   tags:
   - deploy