[drop] Acgsou engine - www.acgsou.com no longer exists

- https://www.acgsou.com/ acgsou.com is redirected to 36dm.club
- @rinpatch do not plan on maintaining the engine [1]

[1] https://github.com/searx/searx/pull/1283#issuecomment-798783585

Signed-off-by: Markus Heiser <markus@darmarit.de>

searx/settings.yml

@@ -737,12 +737,6 @@ engines:
     shortcut : nt
     disabled : True
 
-  - name : acgsou
-    engine : acgsou
-    shortcut : acg
-    disabled : True
-    timeout: 5.0
-
   - name : openairedatasets
     engine : json_engine
     paging : True