Fixed errors when restarting WebApp in Docker

[johannesduesing]

Reason for this PR
When a docker image is built from the WebApps build.sbt, and containers are being deployed, these containers cannot be restarted. Once stopped and started again (or after calling docker restart), the container logs will show the message

This application is already running (Or delete /usr/share/odin/RUNNING_PID file).

and the container will exit immediately.

Solution
Based on this comment, i have change the configuration setting for the PID file. This fixed the problem, meaning i was able to stop, start and restart WebApp containers.

[codecov]

Codecov Report

Merging #23 into develop will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           develop   #23   +/-   ##
=====================================
  Coverage        0%    0%           
=====================================
  Files           10    10           
  Lines          234   234           
  Branches        23    23           
=====================================
  Misses         234   234

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bdac1a5...4b03380. Read the comment docs.

[bhermann]

Looks good.