Make room bar sticky in the schedule viewer (#404)

Author: hongquan

src/pretalx/agenda/templates/agenda/schedule.html

@@ -68,7 +68,7 @@
             locale="{{ request.LANGUAGE_CODE }}"
             timezone="{{ request.event.timezone }}"
             {% if show_talk_list %}format="list"{% endif %}
-            style="--pretalx-clr-primary: {{ request.event.visible_primary_color }}"
+            style="--pretalx-clr-primary: {{ request.event.visible_primary_color }}; --pretalx-sticky-top-offset: 0px"
         ></pretalx-schedule>
         <noscript class="d-block">
             <div class="alert alert-info m-4">