Jdk11 support

[antfling]

支持jdk11的运行

• 相关的测试单元的修改，在jdk11中使用了System.nanoTime()来计算过期时间,所以相关的测试单元修改为100年内不过期为永久不过期的过渡测试方案
• 相关警告可以通过加vm参数--illegal-access=warn 来决定是否显示警告

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ oldratlee
❌ zhonggao.wang

---

zhonggao.wang seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[coveralls]

Coverage decreased (-14.3%) to 62.555% when pulling f10cc29 on antfling:jdk11-support into 463bd35 on alibaba:master.

[oldratlee]

Received.

I will review the code 😄

[devsqrd]

@oldratlee Apologies for writing in English.

Will this code be merged soon? I have a need to support JDK11 with this library, and this PR is exactly what I am looking for.

[oldratlee]

released at v1.6.0-RC1:
https://github.com/alibaba/java-dns-cache-manipulator/releases/tag/v1.6.0-RC1

@antfling @ethanmnrd