Fix Kalender-Page for multiple rooms

src/main/resources/db/migration/V0003__room.sql

@@ -7,4 +7,4 @@ alter table users add column room_id bigint references room;
 alter table kalendertag add column room_id bigint references room;
 
 alter table kalendertag drop constraint kalendertag_day_key;
-
+alter table kalendertag add constraint kalendertag_day_room_unique unique(day,room_id);

src/main/resources/templates/room.html

@@ -21,7 +21,7 @@
 </div>
 
 <div class="mt-2">
-  <img src="/room/plan" alt="kein Raumplan vorhanden">
+  <img src="/room/plan" class="img-fluid" alt="kein Raumplan vorhanden">
 </div>
 
 {#if is_admin}