Replace 60 second sleep in lib/_reboot function with check to ensure instance is running

[NitriKx]

Original poster: https://github.com/4Ply

The instance may take less than, or in more severe cases, greater than 60 seconds to restart. The functions that depend on _reboot() to complete are expecting a working instance, and will fail if the instance is not yet fully functional.

This task is to replace the "sleep" in the _reboot() function with a check that will resolve the function once the instance is running, or fail after a set time.