user page, minor style fix for "Click to enable backfeed"

templates/social_user.html

@@ -179,7 +179,7 @@
 {% else %}
 {% if source.AUTO_POLL %}
 <data class="p-bridgy-listen-status" value="disabled">
-Click to enable <a href="/about#backfeed">backfeed</a>:
+<span class="big">Click to enable <a href="/about#backfeed">backfeed</a>:</span>
 {{ source.button_html('listen', source=source)|safe }}
 </data>
 {% endif %}