Fix indention

[votdev]

With openmediavault 6.7.0 the flex property only supports a limited number of predefined values.

References:

• https://github.com/openmediavault/openmediavault/blob/master/deb/openmediavault/workbench/src/app/core/components/intuition/models/form-field-config.type.ts#L175
• https://forum.openmediavault.org/index.php?thread/49789-representation-in-the-autoshutdown-plugin/&postID=368254#post368254