Fix GC to use a retroarch core

emus/settings.py

@@ -264,7 +264,7 @@ GAME_SYSTEM_DEFAULTS = {
     "gc": {
         "name": "GameCube",
         "color": "7461C7",
-        "emulator": "dolphin",
+        "retroarc_core": "dolphin",
     },
     "mame-libretro": {
         "name": "Arcade",