Configurable RCON IP address

For servers with multiple IP's, ability to bind to a specific interface.

== AT ==
public net.minecraft.server.dedicated.Settings getStringRaw(Ljava/lang/String;)Ljava/lang/String;

paper-server/patches/sources/net/minecraft/server/rcon/thread/RconThread.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/server/rcon/thread/RconThread.java
++++ b/net/minecraft/server/rcon/thread/RconThread.java
+@@ -57,7 +57,7 @@
+     @Nullable
+     public static RconThread create(ServerInterface server) {
+         DedicatedServerProperties dedicatedServerProperties = server.getProperties();
+-        String string = server.getServerIp();
++        String string = dedicatedServerProperties.rconIp; // Paper - Configurable rcon ip
+         if (string.isEmpty()) {
+             string = "0.0.0.0";
+         }