查看日志页面，单行日志长度截断导致下标越界问题

[guobaolin]

单行日志长度大于MaxResponseLogSize时，按限制长度截取字符串实现逻辑存在bug，单行字符串长度是按Byte来计算长度，一个中文占用3个Byte(UTF8),导致截断字符串越界，附上源代码：

        final int MaxResponseLogSize = 65535;
        int totalLogByteSize = 0;
        for (String line : lines) {
            // If a single line of log is exceed max response size, cut off the line
            final int lineByteSize = line.getBytes(StandardCharsets.UTF_8).length;
            if (lineByteSize >= MaxResponseLogSize) {
                builder.append(line, 0, MaxResponseLogSize)
                        .append(" [this line's size ").append(lineByteSize).append(" bytes is exceed ")
                        .append(MaxResponseLogSize).append(" bytes, so only ")
                        .append(MaxResponseLogSize).append(" characters are reserved for performance reasons.]")
                        .append("\r\n");
            } else {
                builder.append(line).append("\r\n");
            }
            totalLogByteSize += lineByteSize;
            if (totalLogByteSize >= MaxResponseLogSize) {
                break;
            }
        }