Remove option groups from version select

validata_ui/templates/schema_info_macros.html

@@ -13,20 +13,12 @@
     <div class="form-group">
         <label for="git_ref" class="mr-2">Version</label>
         <select class="form-control" id="version_select" name="git_ref">
-            {% if tags %}
-            <optgroup label="Tags">
-            {% for tag in tags %}
+            {% for tag in tags or [] %}
             <option{% if tag.name == schema_current_version %} selected{% endif %}>{{ tag.name }}</option>
             {% endfor %}
-            </optgroup>
-            {% endif %}
-            {% if branches %}
-            <optgroup label="Branches">
-            {% for branch in branches %}
+            {% for branch in branches or [] %}
             <option{% if branch.name == schema_current_version %} selected{% endif %}>{{ branch.name }}</option>
             {% endfor %}
-            </optgroup>
-            {% endif %}
         </select>
     </div>
 </form>