Fix GS4 issues.

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/GS4QueryHandler.java

@@ -50,8 +50,13 @@ public class GS4QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
         ByteBuf queryMessage = msg.content();
         InetAddress senderAddress = msg.sender().getAddress();
 
+        // Allocate buffer for response
+        ByteBuf queryResponse = ctx.alloc().buffer();
+        DatagramPacket responsePacket = new DatagramPacket(queryResponse, msg.sender());
+
+        try {
             // Verify query packet magic
-        if (queryMessage.readUnsignedByte() != QUERY_MAGIC_FIRST && queryMessage.readUnsignedByte() != QUERY_MAGIC_SECOND) {
+            if (queryMessage.readUnsignedByte() != QUERY_MAGIC_FIRST || queryMessage.readUnsignedByte() != QUERY_MAGIC_SECOND) {
                 throw new IllegalStateException("Invalid query packet magic");
             }
 
@@ -59,11 +64,7 @@ public class GS4QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
             short type = queryMessage.readUnsignedByte();
             int sessionId = queryMessage.readInt();
 
-        // Allocate buffer for response
+            switch (type) {
-        ByteBuf queryResponse = ctx.alloc().buffer();
-        DatagramPacket responsePacket = new DatagramPacket(queryResponse, msg.sender());
-
-        switch(type) {
                 case QUERY_TYPE_HANDSHAKE: {
                     // Generate new challenge token and put it into the sessions cache
                     int challengeToken = ThreadLocalRandom.current().nextInt();
@@ -123,11 +124,10 @@ public class GS4QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
 
             // Send the response
             ctx.writeAndFlush(responsePacket);
+        } catch (Exception e) {
+            logger.warn("Error while trying to handle a query packet from {}", msg.sender(), e);
+            responsePacket.release();
         }
-
-    @Override
-    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        logger.warn("Error while trying to handle a query packet from {}", ctx.channel().remoteAddress(), cause);
     }
 
     private static void writeString(ByteBuf buf, String string) {