Make gnupg pubkey export an option only in oem-factory-reset

[alex-nitrokey]

Since #758 is merged, users have a option to export GnuPG pubkey if
necessary. Thus, we they do not need to insert a USB drive during
factory reset. Until now the whole process failed just because a user
did not provide a USB drive instead.

This shall be fixed by this commit

[tlaurion]

As wrongly wrote (sorry) in #764 (comment) :

@alex-nitrokey : I would prefer having mount-usb from preceded with a prompt prior of exporting the keys and keep factory-reset outputing normally to /media if not already mounted.

I will merge my changes to that script in subsequent PR for the reownership wizard to work with upstreamed code, and to me it doesn't really make sense to have a factory reset without exporting the public key.

So in this case, I would set the default to N in the factory-reset script prompt, detect if there is USB drive and not fail but continue?

[alex-nitrokey]

So in this case, I would set the default to N in the factory-reset script prompt, detect if there is USB drive and not fail but continue?

Sounds good to me!

[alex-nitrokey]

To add: I am preparing a commit accordingly.

[alex-nitrokey]

This should be fine now :)

[tlaurion]

@alex-nitrokey : conflict needs to be resolved prior of merging and testing

[alex-nitrokey]

Should be good to go again now :)

[tlaurion]

Works as intended.