Fix beatmap background not changing upon joining multiplayer room

Author: Rian8337

src/com/osudroid/ui/v2/multi/RoomScene.kt

@@ -796,7 +796,6 @@ class RoomScene(
 
         RoomAPI.setPlayerMods(ModMenu.enabledMods.serializeMods())
 
-        updateBeatmap(newRoom.beatmap)
         updateInformation()
         updatePlayerList()
 
@@ -820,6 +819,12 @@ class RoomScene(
             return
         }
 
+        val beatmapInfo = LibraryManager.findBeatmapByMD5(newRoom.beatmap?.md5)
+        GlobalManager.getInstance().selectedBeatmap = beatmapInfo
+
+        updateBackground(beatmapInfo?.backgroundPath)
+        updateBeatmap(newRoom.beatmap)
+
         show()
     }