text on the gui becomes unreadable when connect failed

[camilasan]

See owncloud/client#6546
oc fix: owncloud/client@b2fa9ed

Ideas on how to make it better by @jancborchardt:

• Window gets higher when showing error (not so nice)
• Error shows on bottom, left next to the "Back/Next" buttons, if that is possible
• Error shows right of some of the bottom elements like the connection spinner or the "Nextcloud folder is synced to local folder", could just be half-half width of the window

What are other options?

[jancborchardt]

Looking at it again, I think this makes most sense:

Error shows right of some of the bottom elements like the connection spinner

As it’s direct feedback to the spinner, and in case of error the spinner is also not needed anymore.