Include compatible protocol versions in the incompatible version message

Fixes #519

proxy/src/main/java/com/velocitypowered/proxy/connection/client/HandshakeSessionHandler.java

@@ -118,7 +118,8 @@ public class HandshakeSessionHandler implements MinecraftSessionHandler {
 
   private void handleLogin(Handshake handshake, InitialInboundConnection ic) {
     if (!ProtocolVersion.isSupported(handshake.getProtocolVersion())) {
-      ic.disconnectQuietly(Component.translatable("multiplayer.disconnect.outdated_client"));
+      ic.disconnectQuietly(Component.translatable("multiplayer.disconnect.outdated_client")
+          .args(Component.text(ProtocolVersion.SUPPORTED_VERSION_STRING)));
       return;
     }