Allow empty option values in autocomplete select

ckanext/odsh/templates/macros/form.html

@@ -176,11 +176,9 @@ is_required=false) %}
       <select id="{{ (id or name) }}" name="{{ name }}" 
               {{ attributes(attrs) }} data-module="autocomplete"{% if is_multiple %} multiple{% endif %}>
           {% for option in options %}
-            {% if option.key %}
-              <option value="{{ option.key }}"{% if option.key in selected %} selected="selected"{% endif %}>
+            <option value="{{ option.key or '' }}"{% if option.key in selected %} selected="selected"{% endif %}>
               {{ option.text or option.value }}
             </option>
-            {% endif %}
           {% endfor %}
       </select>
     </div>