Added ping interval not to disconnect after 1 minute, websocket

[davidjirovec]

There previously was ping interval configured like this, but it was removed in a3050c2215d4e41b5c22a12c2b96e7fada28c33c. No idea why :)

[denistorresan]

Hi @Parker7123 you forgot to import TimeUnit:

please add

import java.util.concurrent.TimeUnit;