CI: Disable redis errors on write failures

.drone.yml

@@ -7,6 +7,8 @@ steps:
   commands:
   - kill $(ps aux | grep 'redis-server 127.0.0.1:6389' | awk '{print $2}') || true
   - redis-server --bind 127.0.0.1 --port 6389 >/dev/null &
+  # We do not care about persistance on CI
+  - redis-cli config set stop-writes-on-bgsave-error no
   - coverage run -m pytest -q
   - coverage xml
   - sonar-scanner -Dsonar.projectKey=SelfPrivacy-REST-API -Dsonar.sources=. -Dsonar.host.url=http://analyzer.lan:9000 -Dsonar.login="$SONARQUBE_TOKEN"