Update bib.liquid

Author: Rows21

_layouts/bib.liquid

@@ -2,8 +2,8 @@
 ---
 <div class="row">
   {% if site.enable_publication_thumbnails %}
-    <div class="col-sm-3 {% if entry.preview and (entry.selected == true or entry.selected == 'true') %}preview{% else %}abbr{% endif %}">
-      {% if entry.preview and (entry.selected == true or entry.selected == 'true') %}
+    <div class="col-sm-3 {% if entry.preview %}preview{% else %}abbr{% endif %}">
+      {% if entry.preview %}
         {% if entry.preview contains '://' %}
           <img class="preview z-depth-1 rounded" src="{{ entry.preview }}">
         {% else %}