error while marshaling: string field contains invalid UTF-8

Hello there,

Found a bug with a specific program (an interesting one IMO)

```[2021-07-28 16:21:19] WAR Error while asking for rule: rpc error: code = Internal desc = grpc: error while marshaling: string field contains invalid UTF-8 - /usr/bin/sqsh (2922337) -> google.com:1433 (proto:tcp uid:1000)
[2021-07-28 16:21:19] ERR Invalid rule received, applying default action
[2021-07-28 16:21:19] WAR Error while pinging UI service: rpc error: code = Internal desc = grpc: error while marshaling: string field contains invalid UTF-8, state: READY
```

**To Reproduce**
* Install the package `sqsh` (a mssql client) on Ubuntu 20.04
* Connect to a non existent server (in this case localhost)
* OK interaction
_Prompt should popup_ after typing in password
```
sqsh -S localhost
```

* Error interaction
```
sqsh -S localhost -P foo
```

**Screenshots**
# OK Interaction

# Error Interaction

**OS (please complete the following information):**
- OS: NAME="Ubuntu" VERSION="20.04.2 LTS (Focal Fossa)"
- Kernel: Linux X 5.10.0-1034-oem 35-Ubuntu SMP Wed Jun 23 09:55:56 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
- Window Manager: KDE