Fix: [TW] Map detection backend in Daedalian Hymn event

Codes are from old files, so use the old detection method.
Turn on MAP_HAS_WALL in B2B3D2D3

campaign/event_20210624_tw/b1.py

@@ -74,6 +74,7 @@ class Config:
         'distance': 50,
         'wlen': 1000
     }
+    DETECTION_BACKEND = 'perspective'
 
 
 class Campaign(CampaignBase):