if/else blocks that emit content that includes the `=` sign are no longer
supported in recent versions of ansible.

Trying to run the task under ansible 1.9 results in this error:

     variable inserted a new parameter into the module args.
     Be sure to quote variables if they contain equal signs (for example: "{{var}}").

Replace the {% if %} block with the new default(omit) filter/keyword.

For more info see:
https://groups.google.com/forum/#!msg/ansible-project/W9bG0tAI3aU/GFtrD9Ao9EwJ