According to Ethereum official blog, the Constantinople upgrade will be delayed due to security vulnerability which allows attackers to exploit the code of smart contract and steal user’s funds. The renewed upgrade time will be confirmed in the upcoming core developer conference meeting on this coming Friday.
We will continue to monitor the progress on of this event, please stay tuned for further announcement.
Ethereum Offical Blog: https://blog.ethereum.org/2019/01/15/security-alert-ethereum-constantinople-postponement/
19 January 2019