Issue description

I've been using Konsole for years and it works great with tmux. However since a few days ago on unstable small, when I close a Konsole tab, the tmux session "in that tab" gets killed/stopped or whatever....

Steps to reproduce

1. Use nixos-uunstable-small
2. Open Konsole
3. SSH into server
4. Start TMUX session
5. Right-click the konsole server tab and close it
6. Open new tap, ssh into same server again
7. Try to attach tmux

--> https://youtu.be/-hXLPQfoI70

This has been happening not longer than 2 weeks I think... maybe even less than 1 week - not sure how long but not very long.

Technical details

Please run nix-shell -p nix-info --run "nix-info -m" and paste the
results.

• system: "x86_64-linux"
• host os: Linux 4.14.21, NixOS, 18.03pre129183.a3c96fd4de3 (Impala)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 1.11.16
• channels(hyper): ""
• channels(root): "nixos-18.03pre129183.a3c96fd4de3"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs