At register, having a problem during the Google import breaks the flow

[frankrousseau]

When I say I want to import data from my Google account, if I am not logged with the right Google account, I can't change account without breaking the flow.

Reported by @Benibur

[poupotte]

Actually, there is a button to the right top to change gmail account.

However, we could add a button to reopen window if user closes it not on purpose.

[poupotte]

We can now reopen window to import gmail account. I propose to close this issue. @frankrousseau, don't hesistate to reopen it if isn't unclear for you.