Description of problem:

Settings for default discovery templates (PXE, GRUB & GRUB2) are ignored and not used anywhere.

How reproducible:

Is this issue a regression from an earlier version:

Steps to Reproduce:

1. Change value of the setting to different template

2. Build default templates for the TFTP

3. Check rendered templates on TFTP

Actual behavior:
template from the setting is not used.

Expected behavior:

Business Impact / Additional info: