Failures opening a new terminal, when connected (via SSH) to another machine where toolbox is being used

**Describe the bug**
When using machine A, I ssh to machine B (my development machine) and `toolbox enter $container`.
When I `Ctrl + Shift + N` my terminal on machine A, I get the following error: `There's an error creating a child process for this terminal.`

**Steps how to reproduce the behaviour**

Ensure you have 2 machines, machine A **without** toolbox installed, machine B **with** toolbox installed.

1. Open a Terminal on machine A
2. `ssh` to machine B
3. On machine B, `toolbox enter ...`
4. On machine A, try to launch a new terminal instance, **from the instance where you connected to machine B, and inside the toolbox**.
5. See the error

**Expected behaviour**
Toolbox shouldn't have any effect on the machine A's terminal.

**Actual behaviour**
Toolbox errors out, not allowing the user to access a new terminal instance.

**Screenshots**
No applicable

**Output of `toolbox --version` (v0.0.90+)**
`toolbox version 0.0.97`

**Toolbox package info (`rpm -q toolbox`)**
`toolbox-0.0.97-1.fc33.noarch`

**Output of `podman version`**
```
Version: 2.1.1
API Version: 2.0.0
Go Version: go1.15.2
Built: Wed Oct 7 18:21:20 2020
OS/Arch: linux/amd64
```

**Podman package info (`rpm -q podman`)**
`podman-2.1.1-12.fc33.x86_64`

**Info about your OS**
Fedora 33

**Additional context**
Nothing else to add.

Reproduce the two-machine sequence: SSH from machine A to machine B, run `toolbox enter ...`, then launch a new terminal on machine A with Ctrl+Shift+N. Trace the terminal child-process failure and verify that a new terminal on machine A opens successfully while the remote session is inside Toolbox.

Written by the indexing model from the issue text.