Use JGit instead of GrGit now that jcenter is going away.

Update missed mapped name in MDK.

build.gradle

@@ -1,7 +1,6 @@
 buildscript {
     repositories {
         maven { url = 'https://files.minecraftforge.net/maven' }
-        jcenter()
         mavenCentral()
     }
     dependencies {

src/main/java/com/example/examplemod/ExampleMod.java

@@ -48,7 +48,7 @@ public class ExampleMod
 
     private void doClientStuff(final FMLClientSetupEvent event) {
         // do something that can only be done on the client
-        LOGGER.info("Got game settings {}", event.getMinecraftSupplier().get().gameSettings);
+        LOGGER.info("Got game settings {}", event.getMinecraftSupplier().get().options);
     }
 
     private void enqueueIMC(final InterModEnqueueEvent event)