Installing upgrade pack from 8300 to 8400 shows message about default admin password

Installing upgrade pack from 8300 to 8400 shows message about default admin password

When attempting to upgrade from 8300 to 8400 upgrade pack I recieve the message 

System default admin user is keeping the username itself as the password......(picture attached)

I am unsure where to change this is it the posgres database root password within config. I am at a loss where to go to change it. 

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