pulling without remote selected makes pull button unresponsive, also after selecting a remote

[mithom]

when pulling on a new branch, without any remote selected, the pull fails (obviously).
This will show an error message in the pull dialog while keeping this window open.
This allows you to select a remote and try again.
Except that you cannot try again, the pull button is now unresponsive until you close the view and start the pull process again.
Is this intended behavior? at least it doesn't feel like it with the current user feedback.

[love-linger]

Merged.