Bug 451977

SUMMARY
My server have a three-layer SSH protection: SSH key, password, and TOTP. While Dolphin can pass the first one, the rest (keyboard interrupts) cannot be done, and Dolphin just says "failed".

STEPS TO REPRODUCE
1. Set up a SSH server with similar setup (I use google-authenticator as the keyboard interrupt, but you can use any)
2. Try to SSH into it via terminal (you can)
3. Try to sftp into it via Dolphin (you cannot)

OBSERVED RESULT
Failed. (That's what it excaly said.)

EXPECTED RESULT
Keyboard interrupt should redirect to input boxes, and it should pass once I entered all valid informations.

SOFTWARE/OS VERSIONS
Linux: Ubuntu 21.10
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.86.0
Qt Version: 5.15.2