Comment 0 for bug 1755192

This used to work for Ubuntu 14.04 and 16.04.

```
Step 5/7 : RUN add-apt-repository -y ppa:kernsuite/kern-dev
 ---> Running in 4d6412c3d237
gpg: keybox '/tmp/tmpol6z8f79/pubring.gpg' created
gpg: /tmp/tmpol6z8f79/trustdb.gpg: trustdb created
gpg: key 813B0DC8B7D042E7: public key "Launchpad PPA for KERN suite" imported
gpg: Total number processed: 1
gpg: imported: 1
Warning: apt-key output should not be parsed (stdout is not a terminal)
OK
[Errno 2] No such file or directory: 'S.gpg-agent.browser'
```

Dockerfile:

```
FROM ubuntu:18.04
MAINTAINER <email address hidden>
RUN apt-get update
RUN apt-get install -y software-properties-common
```