proposeLocalDir=FALSE option to force end users to actively select a suitable local directory

[rwalke]

Feature description

When a user installs Nextcloud, the wizard uses a default directory that works.
Often, administrators do not recommend this folder as a local directory, e.g. in the Windows OS user's roaming profile.
The user should be required to actively select a local directory.

If the automatic software distribution could distribute an option like
proposeLocalDir=FALSE
to the nextcloud.cfg file,
the Nextcloud wizard would wait until the users themselves selected a suitable directory.

This would help administrators in organizations to promote a certain style of Nextcloud usage.
Nothing would change for individual Nextcloud users.