Clarify execution of upgrade wizards (#198)

Previous text was slightly misleading: It proposed to not execute the optional
wizard. However, from the GUI and the text is not clear that you should
actually click on the buttton "Execute" and then choose "No, do not execute".

Otherwise the upgrade wizard will be displayed in the list of to be executed
wizards and the upgrade will not be considered as done.

This change proposed to execute the wizard with the "Do not execute" option.

Documentation/Upgrade/UseTheUpgradeWizard/Index.rst

@@ -60,8 +60,14 @@ features of the new TYPO3 version.
 
 Go through all wizards and apply the (database) updates they propose. Please
 note that some wizards provide optional features, like installing system
-extensions (for example simulatestatic) that you may not need in your current
+extensions that you may not need in your current
 installation, so take care to only apply those wizards, which you really need.
+Apply the optional wizards too - just be sure to select the correct option
+(e.g. "No, do not execute"). This way, these wizards will also be removed from
+the list of wizards to execute and the upgrade will be marked as "done".
+
+.. image:: ../../Images/upgrade_wizard_install_taskcenter.png
+   :alt: Choose "No, do not execute"
 
 After running through the upgrade wizards go again to the `Database Analyzer`.
 You will be able to execute queries to adapt them so that the tables and