Ghost Environment Variable not set correct

### Which component(s) is affected?

Kubero UI

### Describe the bug

Hi Kubero Team,

by default the Ghost Template sets "database__connection__host". After changing this to "GHOST_DATABASE_HOST" the deployment spins up.

Cheers
AA

### Steps to reproduce

_No response_

### Expected behavior

Connection to MariaDB will be established.

### Screenshots

### Additional information

_No response_

### Debug information

_No response_

Start with the Kubero UI's Ghost Template configuration and compare the default database__connection__host value with GHOST_DATABASE_HOST. Verify the corrected template by deploying Ghost and confirming that the MariaDB connection is established.

Written by the indexing model from the issue text.