Only apply opacity rules to help links in info

Just a quick CSS change to address concerns in https://github.com/reciprocity/ggrc-core/commit/91bc99de365bd2515dbc8e5b62cc562cb969263a#diff-12ddab57569e6fd119b9843fcfd6fd0eR378

Here we restrict the opacity rules to rel="tooltip" &lt;i&gt; tags.