Build: tweak killall to silence error
As we want to proceed if there is nothing to kill, given that our
goal is to have no apt-get processes running.
@@ -28,7 +28,7 @@ jobs:
# networking related issues, and thus holding on to
# `/var/lib/apt/lists/lock`.
# https://support.circleci.com/hc/en-us/articles/360021256633-Apt-Get-Update-Is-Slow-Or-Locked
- sudo killall apt-get
+ sudo killall apt-get || true
sudo apt-get update
sudo apt-get install -y git rng-tools memcached
