Make scan-for-legacy-ender-dragon config work again

Portion of diff was dropped in the mappings update commit.

Also remove the option to remove invalid statistics. The server will
automatically do this now as of... 1.13?, our option wasn't even doing anything.

Spigot-Server-Patches/Add-Velocity-IP-Forwarding-Support.patch

@@ -14,7 +14,7 @@ forwarding, and is integrated into the Minecraft login process by using the 1.13
 login plugin message packet.
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
-index e87c79387..bc74ea2f0 100644
+index 5663a6517..fef899ae0 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
 @@ -0,0 +0,0 @@ import java.io.IOException;
@@ -127,7 +127,7 @@ index 000000000..fdd8708f9
 +    }
 +}
 diff --git a/src/main/java/net/minecraft/server/LoginListener.java b/src/main/java/net/minecraft/server/LoginListener.java
-index 5778a5201..b6a3992a3 100644
+index 58a2f3d28..4df31c828 100644
 --- a/src/main/java/net/minecraft/server/LoginListener.java
 +++ b/src/main/java/net/minecraft/server/LoginListener.java
 @@ -0,0 +0,0 @@ public class LoginListener implements PacketLoginInListener, ITickable {