Ensure metrics UUID is valid

core/src/main/java/org/geysermc/geyser/configuration/ConfigLoader.java

@@ -34,6 +34,7 @@ import org.spongepowered.configurate.yaml.YamlConfigurationLoader;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.UUID;
 import java.util.function.Consumer;
 
 import static org.spongepowered.configurate.NodePath.path;
@@ -107,6 +108,13 @@ public final class ConfigLoader {
                         }
                         return null;
                     })
+                    .addAction(path("metrics", "uuid"), (path, value) -> {
+                        if ("generateduuid".equals(value.getString())) {
+                            // Manually copied config without Metrics UUID creation?
+                            return new Object[]{UUID.randomUUID()};
+                        }
+                        return null;
+                    })
                     .addAction(path("bedrock", "motd1"), rename("primary-motd"))
                     .addAction(path("bedrock", "motd2"), rename("secondary-motd"))
                     // Legacy config values