Replace @Mod.Instance with direct static references

(cherry picked from commit 4b605cc)

src/main/java/com/replaymod/replay/ReplayModReplay.java

@@ -35,8 +35,7 @@ public class ReplayModReplay {
     @Mod.Instance(MOD_ID)
     public static ReplayModReplay instance;
 
-    @Mod.Instance(ReplayMod.MOD_ID)
-    private static ReplayMod core;
+    private ReplayMod core;
 
     private final CameraControllerRegistry cameraControllerRegistry = new CameraControllerRegistry();
 
@@ -51,6 +50,7 @@ public class ReplayModReplay {
     @Mod.EventHandler
     public void preInit(FMLPreInitializationEvent event) {
         logger = event.getModLog();
+        core = ReplayMod.instance;
 
         core.getSettingsRegistry().register(Setting.class);