[Bootstrap] Update bootstrap nodes

[nurupo]

Hello,

We ask everyone to update their bootstrap nodes to use TokTok c-toxcore 
v0.2.2 due to a vulnerability discovered in Toxcore.

You can get the new Toxcore release at 
https://github.com/TokTok/c-toxcore/releases
To learn more about the vulnerability, read our blog post at 
https://blog.tox.chat/2018/04/security-vulnerability-and-new-toxcore-release/

-- 
Regards,
nurupo