Fix conditional compilation.

Assets/Cryville/Crtr/DiscordController.cs

@@ -4,6 +4,7 @@ using UnityEngine;
 
 namespace Cryville.Crtr {
 	internal class DiscordController : MonoBehaviour {
+#if UNITY_STANDALONE_WIN || UNITY_EDITOR_WIN
 		public static DiscordController Instance;
 
 		const long CLIENT_ID = 1059021675578007622L;
@@ -50,5 +51,6 @@ namespace Cryville.Crtr {
 				},
 			}, Callback);
 		}
+#endif
 	}
 }