Fix Can't join: ByteToMessageCodec$1.decode() did not read anything but decoded a message (#893)

Author: basaigh

protocol/src/main/java/org/geysermc/mcprotocollib/network/netty/PacketEncryptorCodec.java

@@ -47,6 +47,7 @@ protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) t
         try {
             config.encryption().decrypt(heapBuf.array(), baseOffset, inBytes, heapBuf.array(), baseOffset);
             out.add(heapBuf);
+            if (in.hasArray()) in.readerIndex(inBytes); // This is required as otherwise the ByteBuf doesn't know it has been read
         } catch (Exception e) {
             heapBuf.release();
             throw e;