Link to the correct tutorial

[Langbart]

Under the latest SVN version [25945], the Starting Economy Walkthrough tutorial is loaded under Learn to Play.

When you start the Tutorial campaign, the Introduction Tutorial is listed first and the Starting Economy Walkthrough is listed second.

A patch to fix the problem has already been created, I just created a ticket so that the problem is not forgotten.

[Freagarach]

In 26702:

Use the Introductory Tutorial as tutorial.

As opposed to the Starting Economy Walkthrough, which is less beginner-friendly.

Patch by: @azayrahmad
Differential revision: ​https://code.wildfiregames.com/D4194
Fixes #6347