Changing admin password after pmm-agent is registered on PMM Server

User impact:

User can get locked out of pmm

Steps to reproduce:

Start PMM docker server
Register pmm-agent

sudo pmm-admin config --server-url=https://admin:[email protected] --server-insecure-tls 

Change admin password with change-admin-password

docker exec -t pmm-server change-admin-password newnew1 

Log out of PMM and try to login with admin/newnew1

Actual result:

Invalid username or password

Expected result:

Login successful

Workaround:

Details:

Also getting "Please check username and password" when trying to change password again and re-registering agent with the new password