Add back option to display current flag icon instead of MDI icon

[divadsn]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Describe the solution you'd like
I would like to see back an option in the settings to enable the country flag icon to be displayed in the navbar like here:

Currently it looks like this here:

Describe alternatives you've considered
I already tried to find the old version of the template to hack it myself, but it seems the commit history is gone.

Additional context
Add any other context or screenshots about the feature request here.

[giterlizzi]

Hi, what was the version of the template that had the language icon selected ?