Warn of insufficient space on Google Drive before uploading

[Noffica]

I did not have sufficient space to sync a 2GB file to my Google Drive which Insync informed me of after spending all the time uploading and then failing.

Insync must inform of such things before the attempt to upload not after, having spent so much time in the attempt.

[roald]

@Noffica I’m sorry for all the inconvenience this cause you. I will add this as a feature request. Thank you.