ssh_userauth_publickey_auto: should accept empty passphrase

[rayrapetyan]

Empty passphrase should be a valid input for ssh_userauth_publickey_auto. Otherwise there is an extra passphrase dialog. It should appear only when ssh_userauth_publickey_auto really fails with empty passphrase.

[antenore]

Well done, thank you!
Can you just remove entirely the commented if?

I'll do some tests later and then I will merge it.

[antenore]

Thanks.

[antenore]

Neat, remember me to add your name in the AUTHORS and in the remmina_about.glade file before the next release.

[rayrapetyan]

Thanks.
Seems this patch is still not ideal. E.g. there are situations when first call to ssh_userauth_publickey_auto ends up with a timeout (e.g. server is temporary busy), it will raise a passphrase prompt window (which is unrelated in this given situation).
Looks like there is no nice way to determine if passphrase is set or not yet. Here are some more thoughts on this issue: https://security.stackexchange.com/questions/129724/how-to-check-if-an-ssh-private-key-has-passphrase-or-not.