impossible to quit the windows when adding a picture.

[dominix]

when writing a new message and when adding a picture,
a window open to enter an url or a file and a comment for the picture.
from this point it is impossible to quit the window.
Neither cancel nor quit nor validate the picture, nor button that close the window allow me to quit and to resume the writing of the message. So I stay stuck in the windows; I have to KILL the App and start again electron-mail.

[vladimiry]

Same issue as #334?

CC @KaKi87.

[KaKi87]

Oh, probably yes.

[vladimiry]

Closing as duplicate of #334.