You'd have to adjust the code for the nospam plugin directly. In general, doing so for a specific template is really easy. At the top, you would add
if ($modx->resource->get('template') == #)
return '';
Replace the # with the ID of your template.
Note: As a rule, you would want to copy the Plugin, and disable the original before you make your modification. This is because if you update the Plugin, it will overwrite your mods.
